Do you have a fat32 hd installed in the laptop?
if so then...

In the KDE menu there should be a knoppix entry in it should be the make persistent home entry. You can use an existing fat32 hard drive or other writable media for your persistent home.

Or just save your edited /etc/hosts file on your hd and link to it. Using this approach I would pborably make an etc directory on your hd and place your new hosts file there, then as root (as an example, your hd may be a different device and have a different mountpoint)

rm /etc/hosts
ln -s /mnt/hda1/etc/hosts /etc/hosts

HTH

~rock