It is nearly impossible to do this.
But a good way exists with the image of the openSUSE-XX-NET images: copy the image content in an directory of an usb-stick, for example oss111 and boot (grub) with following options:
title OSS11.1 Rescue
root (hd0,1)
kernel /oss111/boot/i386/loader/linux install=hd://sda2/oss111 splash=silent rescue=1 showopts lang=de
initrd /oss111/boot/i386/loader/initrd
boot
Why do not use the same behaviour install=[protocol]://[location] for the Live CD? This works well.