As you can see, the problem with isolinux config files is that it has the name of the initrd file among the kernel parameters, despite that it's obviously not a kernel parameter but something the bootloader must handle. As both GRUB-l and LILO (and also GRUB1) handles initrd as a separate configuration option, modifying my script could be a good start if you wanted to convert an isolinux config file to a LILO config file. (Incidentally, loadlin also has the initrd among kernel parameters, but that's only because loadlin receives all the configuration in a single line and all but three kind of them are used directly as kernel parameters.)