VirtualBox in Knoppix 7.0.5 can't run rhel_6.0 x86_64 iso

[rajibando]

Dear Capricorny,
I have observed that you are very patient, especially with people fidgety like I am. Thank you. The <a href ="http://knopper.net/knoppix/knoppix705-en.html"> Knoppix 7.0.5 </a> page contains the above subject line. Please guide. I regularly (nearly exclusively) use cloop with Knoppix to get all my work done.
The cloop line in my grub menu is:

menuentry "Knoppix cloop" {
echo 1
echo 2
linux (hd0,x)/boot/isolinux/linux root=/dev/ram rw ramdisk_size=100000 lang=us apm=power-off nomce xmodule=fbdev tz=/Asia/Kolkata
echo 3
initrd (hd0,x)/boot/isolinux/minirt.gz

My question is: Where do I write "knoppix64" ?