If you can find a way to put the CD image on the HD then you're OK.

"knoppix fromhd=/dev/hda1 Boot from previously copied CD-Image"

This is one of the boot options in the latest 3.3 update.

There are several ways of getting the CD copied, an external CD, via a network or put the HD in an other computer just for the copying.

Have a look below the update announcement on this page:
http://www.knopper.net/knoppix/index-en.html