You need a CD Player program that can save the CD track to disk as a .WAV or .MP3 file.
I downloaded MusicMatch which can do it, but it's not a very good program otherwise.
Since .WAV and .MP3 files are usually very big files, you might also want to ZIP the file to make it smaller. MP3 format won't compress very much, but it might just be that little bit smaller needed to keep from overloading the recipients e-mail box.