Hi Jon - Welcome to the Board
Bad news - you need a floppy drive both to back up and restore according to all the refs I could find on MS
Knowledge Base, etc. MS
Backup - which is what you are using does not write to optical drives, but there is a workaround. If you format a CD - or DVD? in InCd then Windows sees it as a drive and you can backup to an optical drive. Unfortunately a CD is nothing like large enough for an ASR - spanning of CD's is not supported and I guess your laptop does not have a DVD writer.
You may find something like Norton Ghost more useful - that will span multiple CD's
Only other suggestion is get hold of a USB floppy drive.