PO Module - using a combination of RC and RT to generate Invoice

SOLVED

In the PO module, how do you generate an Invoice from a Receipt AND a Return entry? I clicked on the 'Multiple Receipts' checkbox but it only allows me to enter Receipt numbers, not Return numbers which are needed to generate the correct net amount for the invoice.

My workaround was to change the quantities in the Invoice entry screen to reflect the returns that actually happened. This generated the correct invoice amount. But when I used Day End Processing it pushed G/L adjustments to G/L batches that are identical to the entries already generated by the Return entry done earlier. So I had to delete these new G/L adjustments before they were posted to the G/L.