No I don't think it is possible. Since WMC is a MEDIA program it should be possible to tell it which audio output to use, so you can set the default output to the one you want your star trek sounds on and then tell WMC to use another output. But I wouldn't be at all surprised if WMC did not let you do this.
Another option would be to find a little command line utility that can play a wav on a specific audio output and use Launch.