Dynamically change report grouping

Currently our users can filter data but they cannot manually group data
differently without us having to create them a new report with their
required group options.
Is there a way perhaps to hard code maybe 1 or 2 group levels in a reports
and then turn them off or turn them on dynamically depending on how the user
wanted to view the results.
Any help is appreciated.We use a 'Group By' parameter that the stored proc uses to do the
grouping. The results come back in the same format each time of
course, they're just grouped differently. This can sometimes lead to
some icky VB.NET conditionals inlined into the RDL, but in general it
has worked very well.|||Alternatively, group on an expression that is based on the value of a
parameter.
In our case, the client's requirements needed 6 reports but this
technique allowed us to give them one.
The stored proc must return a result set at a grouping level just above
the two alternative groupings.
BrianK
www.bolign.com