You will need an ISO program.
Win-ISO is what I use but there are many others.
Ultra-ISO, ISO0buster, blah blah

Open the ISO in the ISO program and look in /boot/isolinux/
and find isolinux.cfg. Extract that to your HD.
Now open that isolinux.cfg in your favorite editor and change
that cheatcodes as you want them.

I changed my default to
default: sunnyb 1 alsa myconfig=.... home=....

Scroll through the list and you will find different labels.

My default label is:

LABEL sunnyb
KERNEL linux26
APPEND lang=us ramdisk_size=100000 init=/etc/init noapm vga=794 initrd=minirt26.gz nomce nopcmcia nomousewheel quiet BOOT_IMAGE=knoppix

After you have finished editing that delete the isolinux.cfg from the iso than add the version that you just changed. Save your changes and exit.