Running totals via 3 formulas - Capturing group totals for use in another formula.

I have successfully created running totals based upon the logic below.

reset --- goes in group header

whileprintingrecords;

numbervar x := 0;

calc goes next to what is being calcualted

whileprintingrecords;

numbervar x := x + {field or formula};

display goes where you would like the value to show

whileprintingrecords;

numbervar x;

x

At the end of each Group, is there anyway to capture the group total for later use?  My report is currently working as follows:

                               Group 1:   Total    500

                               Group 2:   Total  1000

                               Group 3:  Total     600

Report Footer:         Grand Total:  2100

I need to capture Group Total 1:  500, Group Total 2:  1000 and Group Total 3:  600 each separately.

I have a calculation that I need to perform on each Group total but do not know how to capture that number to be able to use  it in another formula.

Thanks for your help.