Using InScope function

[Trybbe]

Hi I need help please

I would like to create a drill through on my matrix data region. Currently I have managed to drill through on any of the matrix cells but I'm not winning with totals.

So I've been searching for solutions and many seem to suggest the use of InScope function. Now I have tried some thing like this

=Iif(InScope("matrix1_Total"), count(Fields!HC_CAT1.Value, "matrix1_Total"))

but I'm not winning.

My matrix is as follows:

A B C Total
A 1 2 3 6
B 2 3 4 9
C 3 4 5 12
Total 6 9 12 27

I would like to be able to click on any number on the totals and be able to drill through to the sub report.+

Please help