how to total Group Header qty's only

[rwn]

I have a report that is layed out as below. What I'm desiring to do is total the Group Header Qty field only and not include any qty from the Detail section. So far, I have had no success yet. Any thoughts or suggestions are appreciatted.

Here is how the report is layed out. The Details section is suppressed.

Report Header:
whileprintingrecords;
NumberVar MySum2:=0;

Group Header:
whileprintingrecords;
NumberVar MySum2:=MySum2+({Part Master.ONHAND_01}+{Part :Master.NONNET_01})}*{Part Master.COST_01}

Group Header:
PO Receipts.PRTNUM_55;Maxof PO Receipts.TNXDTE_55;Part Master.ONHAND_01; Part Master.NONNET_01; @Ext Total({Part Master.ONHAND_01} + {Part Master.NONNET_01});@ext cost({@Ext Total} * {Part Master.COST_01})
Details Section:
PO Receipts.PRTNUM_55;PO Receipts.TNXDTE_55;Part Master.Cost_01;

Report Footer:
whileprintingrecords;
NumberVar MySum2;

In the Report Footer, this value (MySum2) needs to be the SUM of the Group Header amounts only.