With the latest VirtualDub, you can now open up other formats using plugins.
1. Update to the latest VirtualDub:
http://www.virtualdub.org
2. Download the plugins:
http://forum.doom9.org/showpost.php?p=1055896&postcount=25
3. Follow guides in the plugin zip on how to install.
I thought I would post this so you won't have to use an out-dated program. A few features from VirtualDubMod are not in VirtualDub but hopefully Phaeron will add them in.