Sorry, I could not get your link to work, so cannot see what you would like help with.
If you are trying to animate a character that really cannot be done with Vegas alone. If you are trying to take a character (still or animated) and move it around and through a background that can be done by using ‘track motion and key frames.
Place your character on track one and your background on track two.
Use pan/crop event to resize your character (if needed). Then use track motion to move it around. Your character would need to have a ‘transparent’ background which you can do in Photoshop or possibly you could color/luma key it in Vegas.