Hi,
I've done changes in the kde menu.
For example supose that the source of th knoppix version that you wanna modify is in /mnt/hda5
You only have to edit which files that you want in
/mnt/hda5/usr/share/applnk

have a quick view to the files in this directory, and early you'll be able to do your custom menu.
Note that there are oculted files (.directory)

Thats all!