The easiest way is to boot the knoppix CD with knoppix 2 dma then once at the command prompt.

Code:
mkfs.ext3 /dev/hdc4
mount /dev/hdc3 /mnt/hdc3
mount /dev/hdc4 /mnt/hdc4
cp -Rp /mnt/hdc3/home/* /mnt/hdc4/
Then edit the /etc/fstab and use this line for new /home.

Code:
/dev/hdc4       /home       ext3            defaults        0       2
Reboot (shutdown -r now at the knoppix command line) and you should be using the new /home partition.