problem i am having is im not able to write to slackware lilo.conf from knoppix
Has knoppix mounted your slack partition as "read-only"?
If so, then either remount it as R/W, or just save a copy of the corrected lilo.conf on your knoppix desktop.
Then to install lilo:
/sbin/lilo -C /path/to/knoppix/Desktop/lilo.conf -b /dev/hda
The "-C" option specifies where to find the lilo.conf file if it is not in the default place (/etc/lilo.conf)
The "-b" option specifies where lilo will be installed ("/dev/hda" will put it on the MBR of your first disk)