CoolEdit has been bought by Adobe and is now called Adobe Audition.
Although it is a multi-track editor, mp3's are unfortunately not. If you import an mp3 all you will get is a single stereo track.
If you want to split up the mp3 you will need some sort of filter or algorithm to do it, and there isn't really anything that can do this perfectly. It usually involves setting up a frequency filter that matches the voice range and filter it out. But you'll still get some voice in the music and some music in the voice.