WordPress MU

I posted this first in wp but I guess I should of posted it here. I am running wpmu 2.7.

I want to display a list of author names with the post amount beside it. This part is easy enough but I would like the post amount to be only from a certain category.

IE. if jonh doe post 20 to category 1 and 40 posts to category 2 I would want to display only post from category 2.

-> Jone Doe (40)

If this is possible any help would be very much appreciated.

Thanks