You can use a program called cool edit pro, you can place your audio track in there and chop to the part you want or even loop entire sections for how long you want them to last.
You then put your card reader into the pc, place your phone card in and copy to your card from the pc.
its quite easy but I've been using it for years here is a link to a trial version,
http://www.download.com/Cool-Record-Edit-P...cdlPid=10865343here are a few more that you can use but cost a few Hundred pounds each.
Soundforge
Acid Pro
Cubase
Ableton Live
and of the industries best - Pro Tools
Hope this helps