Is it possible to select a specific shipment when do a Mobile PO Receipt ?

We are trying start using Mobile receiving   ( in a WMS Organization )  and one problem we have is when a specific  PO and PO Line number has multiple shipments we cannot seem to specify which shipment we are doing the receipt against.      I looked at using  MWA personalizations and this is not field for shipment number.    Does anyboyd know of way to allow us to choose the shipment number if more than one is open and exists ?

I was wondering if there is possibly an  Form Function / Parameter that will allow me to  'turn on' this field ?   

Anybody have any ideas of suggestions ?     The reason this is important is to be able to match up the correct shipment number as we go through the AP process,  we need to make sure our shipment number we recieve matches the shipment number the suppler sent to AP matches.