OK, I've finally got my hardware set up the way I want it. What I have is this...
HD Audio going to 7.1 Surround speakers through the back panel.
AC97 headphones and mic coming in through the front panel.
I'm running an Asus P8P67 with Realtek sound on it, with Win XP 64 bit.
What I'd like to happen is - have all sound effects come through my speakers, and have radio transmissions come through the headphones. Kinda like a real plane

It seems this should be very straightforward in Aces High, since in the Sound menu I can choose Speakers or Headphones for voice and for sound effects. However - no matter what I choose, everything comes through every channel.
Any assistance would be most appreciated!
Paul