Add the filter to the image then click on customise filter and then move the
sliders for width & height to get the position you want.
Another way is:
Apply the Cropping Video Filter to a video clip that needs to be censored or
cropped. Once you have applied the filter, you can customize its movement
found under the Attribute Tab. Click customize filter icon and make the
adjustments as needed.
If the censor does not need to move, just put a color on the overlay track
and adjust the color for time length needed and size. Use the Mask Frame
under the Attribute tab to select one of the frames to make your censored
area a bit more fancy.
Use the Overlay track manager to put more colors or images on the various
video tracks to put multiple censors anywhere else on your clips. You can
have five more overlay tracks to play with in VS10.
Or try the 'Moving Parts' plug-in (free trial) from the following.
http://www.stagetools.com/aboutparts.htm
This works with Adobe Premier as well as ULead but I've not actually tried it.