IFOEdit is a freeware and just might solve your problem:
IFOEdit allows users to parse VOB files, remove and add video, audio and subtitle streams to VOBs, create new IFO files, create DVD images. Also basic DVD Authoring.
Here is a guide to help you along:
This Guide gives a quick overview of the 'Patch' method, used to make a PAL disc appear as if it was NTSC or an NTSC disk appear as PAL. This method requires no re-encoding, and takes only a few seconds.
Guide:
I would suggest that you use a DVDRW until you get the desired results and then copy from that, just in case you wont be waisting discs.
Hope this helps