Mass calculation needs to skip referenced parts & ref assembly

I'm producing a drawing document set and often when detailing out an assembly will show an extra part or assembly as a reference.

I'll exclude it from the bill of materials and I'd like to then set the system to not calculate it into the Mass.

I have some standard notes which look for the mass of the assembly when I drop the notes in and right now it's calculating the part and assembly that I have omited from the BOM.

Any ideas?

-Mac

SolidworksDrawings And Detailing