Sound trouble...?

Hi,

I need some major help to sort out my sound hardware.

I have a Dj mixer connected to decks ect ect.

I want my sound out of my computer to go into a channel into the mixer (easy enough) BUT then the master OUT of my mixer to go back into my computer so I can use my 5.1 surround sound speakers connected to my computer. Hope than makes sense although heres a diagram:



Comp ---> Mixer -----> Comp=speakers

I somehow need the sound card so bypass all other inputs and only allow sound from LINE IN to go to the speakers? Is this possible? Do i need two sound cards?

Hope you pros can help

sunny

any idea anybody?

I did a little research and found that i need something that converts a phono, into 3 PLUG OUT which can connect directley from my mixer into my speakers.

Is there anything out there that can do this. A comparison to this is connecting a games console or phono output to a 5.1 computer speaker system, without the need for a computer?

thanks

sunny