donko1,
You won't be able to copy the files on your Zip Disk Straigt to the CD drive unless you are using that as a backup. You will need to user the master outs or the optical out's on the VS and plug them into your computer's line in and recorded it onto your computer using a program such as CoolEdit or Sound Forge, save the recording to a .wav file then burn your CD.
That's the only way. The Zip disks are Roland's own format and can't be read (in any audio format) on the computer.
Hope this answers your question,
Porter