You cannot copy a DVD to a DVD with a CD-burner...but you can rip a DVD and make a VCD or SVCD and burn that on a CD (for good quality you will have 2 CDs) and most portable DVD players will be capable to play them...have a search on the net with our best friend
Google and look for
DVD rip .
Be aware that a reasonable fast machine is required, to rip, cut and encode a complete DVD can take up to 24 hours on a 500 MHz machine.
Programs like DVD Copy plus or VCD cutter come to mind
