How to change the Qty of second model displayed using Column Model/Rep option in Creo Parametric 4.0

Hi,
In Creo 4.0, is there any way to change/show the quantity of items (not bulk items) as "REF" or "AR" in BOM which is having multiple assemblies?
I could be able to change the values in BOM with single assembly (using relations - "rpt.rel.<User Defined>")
But for multiple assemblies BOM which I created using "rpt.qty" & "Column Model/Rep" I am not able to change the qty values.
If I use rpt.rel.<User Defined> parameter, then I am not able to add second assembly using "Column Model/Rep.
Can someone please help on this question.

Thank you!!