FSX & 5.1 surround

I'm trying to run FSX sound by using 5.1 surround system.

My aim;

Front 2 speakers: the engine sounds

Rear 2 Speakers; Atis

Center Speaker: flightdeck sounds & cabin announcements


I have managed to get the cabin announcement out of the center speaker but having trouble trying to get the rest of iy setup. I'm using Virtual Audio cable but can't workout how to setup the batch file so only certain speakers are used.


Any ideas??

Thanks
Michael