I'm not familiar with your radio, but here's a suggestion. Hook the flaps into the flap channel with a Y-cord. Slave the gear channel to the aileron at -100% of aileron travel, then disable the gear switch. Don't know if it will work for you, but it works OK for my Airtronics!

The other option would be to leave the ailerons hooked up the way you have and hook the flap servos to the gear channel with a Y-cord... then your gear switch would drop your flaps and you just leave the flap switch alone...