Fitting a DVD on a 700mb CD as Xvid or Divx? Help plz!

Hi all im kinda new at this but i want to get it right.
Im trying to fit a DVD i already decrypted on a cd as divx or xvid at good quality.
Im using ImTOO dvd ripper platinum settings at. But the resulting rip is to large for a 700mb cd. So ImTOO has an option to split at 700mb. What this does is cut of the ending. Dont want that! I guess i want the best quality settings i can get for that space. But ive tinkered around at diferent resolution sizes but cant get it right. Is there a way to calculate this?
Any ideas? Thanks.

Yes, you require a bitrate calculator.

Have a look here.

With the video you’ve already got you could recompress it with Virtualdub to a smaller size.