There are serval options to do this
1- use
MPEG Video Wizard to edit out commercials. If you are doing a half hour show you will generally end up with 3 segments which you can combine back into one file using TMPGEnc's mpeg tools section.
File>mpeg tools>merge and cut
2-once joined then you can use
Simpledivx to convert to divx
OR you can follow this guide:
Here and use TMPGEnc DVDAuthor to load the original file and edit out the commercials with that, author the disk to a folder then follow the instructions in the guide.