Changing the volume of Windows programs (individually, not global)

This sounds like a hellish program that takes over the user's computer, but I'm really trying to make a pro开发者_StackOverflow中文版gram that changes the volume of other programs based on a set of rules.

I play WoW and when I raid it is hard to balance the game sounds with Ventrilo and most annoyingly I can't play music if I want to hear the other raiders well. I want to create a program that turns the sound of WoW and my music down whenever Ventrilo outputs sound.

I just need to know if it is possible to do this and, if so, where I should be looking. I searched around and all the questions I saw were global sound and the program's sound, but not the sound of other programs.

Any language is okay, I can adjust accordingly. C or C++ are my first picks. I plan on making a UI for this and releasing the program for others that have my sort of problem. :)