Is that the demo song that has drums, guitars, bass, vocals and everything? When you open it in N-Track, it unpacks all the wav files to you're hard drive, so you can do whatever you want to any of the tracks. Remove the vocals, solo the vocals, pan the vocals all the way to the right, make it sound like the singer is in the bathroom. Why do you think you won't be able to manipulate the vocals? Did you try it yet?