It's other way around. You create the report variables that do the same calcualtions as fields in the group footer now and reference them in the group footer and your calculations.

>Thank you, bless you but what do I put in the var's? Sure they need to refer to the group total field but how do I refer to a field that hasn't a name but is the sum() of a group column.
>
>>You would use report variables instead.
>>