there is some software called penteo that can convert from stereo to surround sound.. and there's a ton of stuff on google tellin u how to do it.
but.. why would you wanna make ur beats surround sound?
the average listener is not gonna have the surround setup when they're playin ur joints, unless it's atmospheric shit for DVD or computer game or something i wouldn't even bother
but saying that, who knows it might turn out to be the future i know they are setting up HD radio stations with surround music.. so don't let me discourage u
look into penteo
pz