I don't see a way to access the PART NUMBER (The one that shows up in the BOM as defined in the configuration properties menu, not through the very common but incorrect way of defining a part number through a custom property)

I do not see a way to access the part number through the API and when I try to set a custom property "PartNo" to "\$PRP:"SW-BOM Part Number(BOM Part Number)" I cannot get the api to resolve this value using the , or any linked internal SolidWorks value for that matter using the CustomPropertyManager Get5 method. I can get it to show "\$PRP:"SW-BOM Part Number(BOM Part Number)" as the value set but the evaluated value only shows blank.

Any ideas?