Playing sounds over the microphone in c++

I am making a program in C++ for Windows XP that requires sound to be played so that any program that is curre开发者_如何学Cntly recording the microphone can hear it, but it will not come out of the speakers. There seems to be no "real" way of doing it, but it is possible to go into "sndvol32 -R" and set the Wave out mix or similar as the current input device. Then you can turn the master volume to 0, play the sound, turn it back up, and reset the input device to the microphone. Is there a way of doing this transparently, or setting the current input device using functions, so that you dont have to see sndvol32 pop up?

Thanks

Doing this would require a complicated kernel-level driver.

Fortunately for you, someone has already done this (it's not free, but it's a fantastic program).