OK so you only need the audio.
Bring the content in the timeline. Click "Make Movie", select "Create AVI file" and in the "Settings" dialog, uncheck "Include video in AVI file". Therefore, your result will be an AVI video file, with audio only. That's all you can do with Studio. Then you have to find another program to extract the sound to another format (say wav or mp3) if you want to burn an Audio-CD.