Soundforge: Removing Vocals in a track and vice versa

[Grafdude]

I was wondering if its possible to remove backround music from a track so I could only hear the voices from the track, and vice versa.
If not, then what program would do the job?

[That Guy]

Vocals are usually recorded in mono and put equally into the left and right channels. They removed by programs (as best as possible) by inverting on of the two channels and putting it up against the other. This cancels the vocals out (most likely with other parts as well). To the best of my knowledge you cannot get a perfectly clean removal of vocals.