Getting Percentage Over Subtotal in Matrix

I worked on a matrix report that needs percentage of each row against the subtotal of the second row group. There are 3 row groups. I looked around and tried different things like InScope(), Sum() with scope, etc. Nothing worked.

The problem was solved by a work around. So instead of trying to get the subtotal from the dataset, I used the ReportItems! Expression to get the subtotal directly from the subtotal cell. This can only be done in SSRS 2008 because in SSRS 2005, the subtotal field is not exposed. Here is the expression used to get the percentage:

=Iif(reportitems!txtEnvironmentSubTotal.Value is nothing, nothing, Format(SUM(Fields!Test_Check_Count.Value)/reportitems!txtEnvironmentSubTotal.Value, "0.0%"))
-- Ke