Hi,
As part of the Nero suite of CD burning programs, there is one called INCD, which only works with CD RW disks, however, by using it, the CD RW is seen as a hard drive by the computer and you just copy files to it,by drag and drop in Windows Explorer or through a smallbatch program.
Note that existing backups will be overwritten, if the file names are the same. Also this method does not provide any compression, which may fill up your CD if you have a lot of data.
Your concern over backup programs and restoring is understandable, however, there is a shareware program called Back2zip available (about $29 US if you don't want annoying popups all the time) which compresses to standard Zip files. It does automatic backups at predetermined times. One limitation of this program is that you can only select folders to backup, not individual files.
As a general rule I recommend that you use one CD RW per working day to ensure that if the CD RW fails or the backuped up data is corrupted, you still have a recent backup.