
I created a drop shipments PO. I go to "ACTION -> FUNCTION -> DROP SHIPMENT -> GET SALES ORDER", afterwards i choose my sales order
Several things will be copied over from my sales order to my purchase order screen for example my items, quantity and the shipping address.
However in my sales order, there is another standard field called "your reference" which i would like to bring over to my purchase order (drop shipment)
Is there any standard way to do this ?
By standard no. The routine that handles this cares more about copying over line level detail than it does header level detail.
If you wanted to modify the routine you could look at using an event subscriber to codeunit 76 "Purch.-Get Drop Shpt." to event OnCodeOnBeforeModify. That event is handling the interaction of the Purchase Header and Sales Header to pass data from PO to SO mainly but the procedure this latches into will modify the purchase header too.