If possible, in future I think you guys can simply add an extra column to the generated report / csv that gets created, perhaps titled “AusPost_Charged_Discrepancy”?

For AusPost comparing What Was Charged minus What was Estimated/Quoted

In terms of creating a formula for “Charged minus Estimated/Quoted”, I can do this manually I guess as follows;

=X2 (shipping inc gst) + SUM(AG2:AQ2) [All other charges inc GST] minus DL2