>Perfect, the code in the When event makes the job. But WHEN() only return .t. or .f., i want to perform an ActivateCell for that cases which the control return .f. Where or How can i do this?

How about this for the When() event:

Do Case
    Case Incidencias.Clase = 'D'
          this.Parent.Parent.ActivateCell(this.Parent.Parent.ActiveRow,4)

          return .F.

     Case Incidencias.Clase = 'B'
          this.Parent.Parent.ActivateCell(this.Parent.Parent.ActiveRow+1,1)

          return .F.
Endcase