View a Subform field in a "List View"

View a Subform field in a "List View"

Hello Everyone!

   I am looking for a solution to be able to view a field in a "Subform" along with other fields from my main module. 

Example:

I have a module called "Customer Orders" where I enter purchase order numbers in a "Subform". Sometimes I have one purchase order for a customer and sometime I have many purchase orders for that customer.... hence the "Subform". I am trying to track my last purchase order number entered so I won't duplicate a purchase order number for the next customer order.

Any ideas would be much appreciated.

Thank you

Rich