Backup/syncing (to CD-RW) software question

I need software to backup or sync files to a CD-RW disk as files and folders, not as a special backup or zip file. It needs to be able to schedule burns, operate unattended, and NOT eject the disk when done. I’ve looked at various packages and so far all fall short in one way or another. I’m doing this for someone who wants to make “idiot proof” (read: no user intervention) scheduled data backups onto a CD-RW disk. If you tell me CD-R disks are more compatible with more readers, I agree. However, that’s not what he wants.

If you have any ideas about this, please let me know. I’m finding it hard to make it simple.