Audio Routing utility

Does someone know a good and free Audio Routing utilty under window7 system.

I need it to route my audio out to mic audio in
(I want to test my audio reaction programm with external player as if it was in my audio in)

Thx in advance
Sebastien

Try jack: http://www.jackaudio.org/

Yes, I tried
but i didn’t manage to route my media player to the Microphone input.

I keep trying.

I don’t think that’s the right approach. Try using jack as your default output and default input. This means that all audio will be sent to jack, which is also the input so your application will respond to your audio.