Row group 'footers' in matrices

I am trying to create a report that will append a calculated row of
percentages to the end of a group of test results. The results are
grouped by 'Category A' and have different subcategories. But
overall, I want to generate percentages for each column in 'Category
A'. The columns of Category A consist of Pass, Fail, and In
Progress. I want to be able to have a percentage of all the passes in
category A, but still have that distinction between a subcategory in
category A.
I have designed the matrix to look like such:
Static
Column
Category A | Sub Category
and I want it to produce a result like such:
Pass Fail In Progress
Category A Sub Category 1
1 3 0
Sub Category 2
3 0 1
Percentage
50% 37.5% 12.5%
Category B Sub Category 1
1 3 0
Sub Category 2
3 0 1
Percentage
50% 37.5% 12.5%
It is easy to format within Crystal Reports, but I have been mashing
my brain all day and I haven't found how to do it within Reporting
Services. HELP.Here are the layouts again. I didn't realize that it was going to get
ruined when it posts.
.Static Column
Category A | SubCategory
.................................P .F .IP
Category A Sub1 3 1 0
..................Sub2 1 2 1
..................Percentage 50% 37.5% 12.5%
Category B Sub1 3 1 0
..................Sub2 1 2 1
..................Percentage 50% 37.5% 12.5%