Vegas Video should be able to use any codec on your system. To see what else you got try this:
1. Have some video on the timeline.
2. File, render as... select AVI, from the window that pops up then hit custom button
3. Now select the Video tab, Video format shows uncompressed, click the down arrow to show additional choices.
You should be presented with a list of all the codecs currently installed on your sytem. Select one. Depending on your selection other options may or may not be grayed out.
I'm not sure I follow your answer, SonicBoom. When I go to that location (in VV3), it's referring to the location of the preferred video capture application to use. Or, does it mean something else?