I'm curious whatever happened to people actually doing online searches and whatnot to solve what they want to do before just posting a question on a forum and waiting for an answer--in my opinion, that's part of the fun of learning something or fixing something, and it helps you be more self-reliant. But anyway...
So, this is more difficult than you might think. While vocals are recorded as independant tracks from other parts of a song in a recording studio, what shows up on a CD is essentially an mix of all sound tracks that compose a song, all on one track--there's no separation of vocals or instruments or beats (unless for example the vocals are only on the left channel and everything else is on the right channel, but I don't think this typically happens). So it's nothing so simple as to being able to "extract" the vocals track data. You need some sort of software that recognizes the difference between vocals and music. I believe Winamp player has (or had) a plugin that did this--it essentially attenuated everything that it found as music, and did not attenuate what it found as vocals. However, there was always some weird echo of the music, or some vocals were not recognized or something like that--it didn't work TOO well in my experience. However, that is a free option--perhaps there are more expensive options that do a better job, but I'm not quite sure.
After doing a quick google search--which is probably what you should have done in the first place, I came up with this for extracting vocals from a song:
FOREVER by Stratovarius - Extract vocals from a song
No idea if it's any good because I have not tried it, and no idea if it extracts the vocals and records the vocals, or records the song without vocals, but it seems to be another option. Here is another that will extract and record the vocals to a file:
Dexster Audio Editor - Edit audio files visually.