Ulead VideoStudio 7 - blurring someone's face (mosiac style)

[Joe Blow]

I have Ulead VideoStudio 7 and Im trying to figure out how to digitally blur a spot of the video (Cops style). You can use the mosiac filter to do the whole screen, and that is the effect I want, but I want it contained to a small spot, like someone's face, not over the whole video. Is there any way to achieve the effect I want with VideoStudio 7?