How would I enable a hotkey for OS X that activates a keystroke in Windows?

I installed Parallels to use Ventrillo on windows to talk to people while I'm on my mac. And it works fine now, but I have it where ithe mic is always on, which has some problems. There's a bit of a delay o it cuts off the first few seconds of whatever I say, and if my speakers are too loud someone else talking will trigger it.

Vent has a push-to-talk feature but Parallels only captures my keyboard input while I've got my mouse over parallels. Is there any way to make it to where I set some kind of hotkey in OS X, and then that hotkey will make parallels do a keystroke which would activate the vent hotkey?

I'd perfer it if all this can be done with vent still minimzed, but if not, I'd still like to know how to set up push-to-talk from OS X.