RE: Can you do this? And How?
I have my 9C set up with what you describe on switch C: sw up, normal flight.
sw center, up elevator=up spoileron and down elevator=down spoileron
sw down , up elevator=down flaperon, down elevator=up flaperon
I have flaperons under the "flaperon" menu and the spoilerons in Pmix for elev to flap.(sorry, I'm at work and can't remember for sure which one, but thinks it's #2) with 75% travel both ways on both.
If you can't figure it out from there, let me know and I'll bring the radio with me tomorrow and send step by step to you.
Roy