How do I turn off my voice and not the music while livestreaming?

[Solsikkegaard]

I really really want to livestream - but I don't want people to hear my voice, only the music I am hearing.
Is there a way to correct this?

And another thing is when I put my headphones on, it refuses to record the sound that comes out from them. It captures my voice fine though, but not the music when I have headphones on.

I saw this thread: http://www.livestream.com/forum/showthread.php?t=5201
but could not find any help.
I am using a Mac OS X 10.6.8 (Snow Leopard) and yesterday I updated Livestream Procaster to version 20.3.0M.

Please help ?