Be able to view purchase order details in statements and main invoice window


With the new invoice system, we've started using the purchase order field rather than the reference tab which we have always used for our client's order numbers.
The purchase order field does not appear in the Invoice list window (very hard to search for an invoice without that option) and we've just noticed that statements do not list the purchase order field, but rather the reference field. Customers have denied our statements as they can't reconcile our purchase order numbers with our monthly statements.
Going back to using reference field for purchase orders - beware if your customers also need purchase order numbers on statements.
Does anyone have a way to list purchase order numbers on monthly statements?
Is there an option yet to list purchase order field on the Invoice screen?