The factor regression model, or hybrid factor model, is a special multivariate model with the following form.
                                          y                                n                          =                  A                                      x                                n                          +                  B                                      z                                n                          +                  c                +                              e                                n                                  where,
                                          y                                n                                   is the 
                    n                -th 
                    G        ×        1                 (known) 
observation.
                                          x                                n                                   is the 
                    n                -th sample 
                              L                      x                                   (unknown) hidden factors.
                              A                         is the (unknown) loading matrix of the hidden factors.
                                          z                                n                                   is the 
                    n                -th sample 
                              L                      z                                   (known) design factors.
                              B                         is the (unknown) regression coefficients of the design factors.
                              c                         is a 
vector of (unknown) 
constant term or intercept.
                                          e                                n                                   is a vector of (unknown) errors, often white Gaussian noise.
Relationship between factor regression model, factor model and regression model
The factor regression model can be viewed as a combination of factor analysis model (                                          y                                n                          =                  A                                      x                                n                          +                  c                +                              e                                n                                  ) and regression model (                                          y                                n                          =                  B                                      z                                n                          +                  c                +                              e                                n                                  ).
Alternatively, the model can be viewed as a special kind of factor model, the hybrid factor model 
                                                                                                                            y                                                        n                                                  =                                  A                                                                      x                                                        n                                                  +                                  B                                                                      z                                                        n                                                  +                                  c                                +                                                      e                                                        n                                                                                                      =                                                                                  [                                                                                                                        A                                                                                                                                B                                                                                                                ]                                                                                        [                                                                                                                                                      x                                                                                      n                                                                                                                                                                                                                                      z                                                                                      n                                                                                                                                            ]                                                  +                                  c                                +                                                      e                                                        n                                                                                                      =                                                              D                                                                      f                                                        n                                                  +                                  c                                +                                                      e                                                        n                                                                                              where,                               D                =                              [                                                                                A                                                                                        B                                                                        ]                                   is the loading matrix of the hybrid factor model and                                           f                                n                          =                              [                                                                                                      x                                                              n                                                                                                                                                              z                                                              n                                                                                            ]                                   are the factors, including the known factors and unknown factors.
Factor regression software is available from here.