RE: Mixing on a plane
Janone,
Sorry to hear you are on the pain meds...be careful with those!
On the programming question, I am not familiar with the radio you have referenced. But if it is not what we refer to as a computer radio you really can't perform the mixing functions.
The general procedure and example though is to identify a master channel (say rudder) and a slave channel (say elevator) and then tell the transmitter to provide elevator deflection when the pilot provides a rudder input. The amount, rate and direction of the interaction between the rudder and elevator in my example are all customizable as part of the programming and are usually dialed in through trial and error.
Either way though, the best place to start is with the manual that came with your radio.
Good luck to you...
Tom