Using an Output Device as Audio on Procaster?

[Overrice]

Hello! Sorry for Double-Topicing but this is a whole other Problem:
As written in my other Topic, i wanna stream with the Gamesound and i use Windows XP, so there's no Stereo Mix supported. Now, if i could Select an output Device as my Audio-Stream, I'd be fine, cause I can run VLC in the Background, so that i get my Voice on the Output device.
Would be really kind, please respond as fast as possible!
Overrice