Jr XP8103 programming

Hello all, I am interested in setting up my transmitter in flaperon mode, using the flap mix mode to control both flaperon and spoileron configuration. I wish the flap movement to go up when the 3 position switch is in the up position, and the flap movement to down when the 3 position switch is in the down position. I can program this using the neutral/up position, or the neutral/down position of the switch, but cannot get both functions to work by merely moving the switch up or down. I have installed two servos in the wing to control the ailerons. Please help. Richard Simonia