Sound the possiblility of choosing which stream

I have an old game which I have set to output no sound,
and have deleted all sound files. It seems to have some
remaining sound set into the body of the program.
I am left at the moment with the choice of sound or no sound
from the game.
I would rather have music playing in the background via
Winamp, but I hear both sets of sound together, making
a racket.
Is there some way to block the output from the game
without blocking Winamp?

Miles