Customer Tracker -> Shipments (add field not in "collection")

On Customer Tracker -> Shipments (all), the collection shows a bunch of fields that we can add to the grid. HOWEVER, it doesn’t show PO NUM, something we would like to display next to invoice #.

What sort of steps do I need to take to add a field not listed in the collection?

Thank you.

If there are available character fields or sometimes you can hijack a standard comment in the collection you can run a post processing bpm on the method that get the shipments and populate the po num.

If there are no available fields then it would require a customization to add the column and then populate.