Forcing flap position with FSUIPC

I have a set of flight data recorded in a real aircraft and I want to use FS to replay the recorded data. I use FSUIPC to position the aircraft and set the 3 angles (pitch, bank, heading) and it works perfect. In fact, I have to set the slew mode to have i working really perfect.Now I want to set the landing gear position and the flap position according to the recorded data. But this does NOT work. I use offsets 0x0BEC, 0BF0, 0BF4 for the gears and offsets 0BE0 and 0BE4 for the flaps. It seems I can't force the gear/flap position using FSUIPC.Do you know any way of forcing these values through FSUIPC?Thanks,Eric