Bootable CD customization

I need to be able to create a very particular bootable cd for SUSE. I have an app that I want to run at boot time that i normally do by adding a call to it in the script boot.local . How can I add this functionality to a SUSE bootable/live CD? From what I can see, there is no boot.local on the live CD, the iso image only contains the kernel,initrd,stage2_eltorito and grub menu files.