Win 7: Controlling MULTIPLE audio volume setting with hotkeys

Not sure that this is the correct sub-forum, but its Sound related.....

I have a specific requirement to fulfill regarding the default Windows (7, ultimate, 64bit) volume control.

I am running a racing simulator.
I have 1 sound card(external via Firewire)

There are several programs that generate audio for the simulator experience:
- the in game sounds
- Teamspeak
- Dash/pit control s/w
- Crew Chief/race engineer s/w

The 4 sources are consistent, and they are opened in the same order for every session (this is important, at least for the default for Windows sound mixer as it creates an audio channel, sequentially, I guess as they attach to the audio buss)

I need to control the volume of these 4 elements with hot keys ( that I can bind at my discretion, since I have many keys re-mapped for other in-car controls). For Example: I would like to control Team Speak volume by assigning Increase Volume to the "K" key, and the Decrease Volume to the "L" key. I don't require visibility in game (although an overlay pop-up would be fine, and a permanent display overlaying the in-game would be ok too. As long as I scan control a specific output with the keys I set, really that's all I need. \

I know I can write a script to bind two keys to the global windows Master Volume control (and that works fine if I had to do it that way), but I cannot make the script select any other channel. I can control a different channel with UP/DOWN arrow keys, but first have to Focus Windows on that slider (but not with the script). Something I cant do in the middle of a race. Thus why binding a key is important.

Thanks for your time this morning.
Steve

I have a MOTU 828 MKII that I retired from my studio when I upgraded it- thats my audio interface.

I never really thought about whether the various programs I'm using could be assigned somehow to a buss or something using CueMix, but that's far above the solution I was looking for. the fact that I can control the default s/w mixer in Win7 via keypresses given me hope that there is a way to do it, maybe with a script or a better written s/w mixer.

Thus mix quesstion :-D