I have an integrated sound card with dolby sorround support and i have also a dolby 5.1 system. In the front of my chassis i have 2 jack(one for mic and another for headphones). Now i would hear things of mumble in my headphones( http://tinyurl.com/353cvt ) and everything else(like playing games, listen to music, etc...) in my normal speakers.
Is it possible?
The front connectors are connected to the same physical output from the audio card as the 5.1 output in the back, so what you're asking can't easily be done.
You'd need a secondary soundcard to do what you describe. However, with such a setup, the audio from your 5.1 system will be picked up by your microphone and sound kind of loud to everyone you're talking to.