Running Totals that need RunningTotals - How ?

[msny]

I have a CR report that requires I use a running total field in a formula and also the Next() & Previous() functions. The formula is then placed unto the Detail line. If I add another group where I need to summerize the forumla Detail it says I can't do that on a running total field or with Next(), Previous().

I know there must be a way to do this. Any ideas on a workaround ?

Thanks !