4GL Report SUM problem

I'm running Informix 4gl v. 6.05 on an HP 9000 running HP-UX 10.2. My problem: I created a REPORT and have "GROUP SUM" and "SUM" fields. The main program passes an array to the report. The SUMs are performed on one of the arrays elements. In the course of Printing each row, I may have changes to the value in that field. The modifications are done directly on the array field. The new values print out correctly, but are not reflected in the SUM or GROUP SUM. Only the original values are included. Any way around this other than creating a "value_change" variable and modifying the SUM total by the variable's total? Thanks, Michael Hoffman