I bet you could do it in Vegas by creating a new video track, then making a mask and blurring that mask, then create a motion track (if needed) and have it stay on top of the number.
I've never made a mask in Vegas, however do a search for it on yahoo. "Vegas Video Tutorial" and I bet you'll find your answer.
Good luck... PS if you find how to do it, hit me up. I'm curious as well.