Channel 1--right aileron
Channel 2--Y harness to the elevator servos
Channel 3--Throttle
Channel 4--Rudder
Channel 5 empty
Channel 6-- Left aileron IF you want to set up flaperons (ailerons that can also function as flaps)
Channel 7--Left aileron IF you want to program aileron differential (more UP throw than DOWN throw, helps with adverse yaw)
Channel 8--empty
. The battery can go in any unused channel (9/B is the battery channel, normally).

You might be able to use CH 8 for the other elevator servo, and program a mix, but I'm not sure how, or if it's worth the hassle.

I would recommend using channel 6 for the left aileron; you can still program differential by another method. The 9C manual has all this in it.