Well there is some question as to the legality of Ripping commercial DVDs, even your own DVDs ripped for your personal use.
I've never ripped a DVD to an AVI (or mp4) file but that would be the best option, a "DVD Ripper" that outputs to an AVI file format. A common one I've heard of is
WinX DVD Ripper Platinum for $36US but I've never personally tried it. Since it can be purchased online I'm sure you can get it on your side of the pond too, maybe with paypal? but you would need to make sure it handles PAL & your encryption methods if they are any different then ours.
You might wait for some other ideas, maybe somebody knows of a freeware version that works for commercial DVDs.