I have a button on the Projects form to open the Customer Orders Quick Entry as a linked child. I have some orders that have a CoNum matching the ProjNum of some projects, so the idea is when you open the linked form, it must show the order that has the same identifier. However, the Customer Orders Quick Entry has SLCos has its base IDO so when the form opens it doesn't show the lines of that order. The lines grid's source is the SLCoitems property, that is a subcollection.
Is there a way to link a property of that subcollection in my Projects button, or a way to refresh the subcollecion when the linked form opens? Every thing I have tried results in this message:

I know you can add a collection refresh handler in the LoadBoundValues event, but I want to leave the Quick Entry form in vendor scope.
Thanks in advance.