aggregate function in the argument to another aggregate function

Hello all,
I am new to SQL Reporting services and I am having trouble performing a
group sum. I Currently have a group within another group the embedded
group (group2) is performing a group sum
(=3DCount(Fields!FacilityTemp1.V=ACalue/Fields!Temp2.Value) and this works
fine but now I would like to use the outside group to perform a sum of
all values within group2 however SQL reporting Services does not allow
aggregate function in the argument to another aggregate function. Does
anyone no how I can simply get around this. Expression that does not
work:
=3DSUM(Count(Fields!FacilityTemp=AC1.Value/Fields!Temp2.Value)
Thanks=20
ChrisSince this question is specific to SQL Server Reporting Services, you
should post it in the microsoft.public.sqlserver.reportingsvcs group.
Razvan