Adding a blur over a section?

[TheGlow]

Hey, quick question which I hope is simple.
I've been recording some game footage and unfortunately Blizzard likes to put friends real names on the text box.
How can I blur that area out as I'd rather not throw everyones full names out there.
It's always a specific section on the screen so is there something in virtualdub to just drag a rectangular section over and apply a blur?

[jagabo]

In VirtualDub you can use the fill function to fill a defined rectangular area with black. Or some other color. You might be able to use some of the de-logo filters with a few tricks to blur a box.

[shekh]

You can setup with internal filters like on picture (I used gauss blur, just assume it is box blur)
The mask needs to be black\white picture where white is the area to blur

Or you can avoid painting and use fill (first fill everything with black and then area to blur with white and name last fill as "mask")