Part Custom Property Question

When creating a new Custom Property, Lets say "Stock" and clicking on the "Value / Text Expression" Column cell I get a drop down list. If I select a property from this list I get something like this:

"SW-Mass@Part1.SLDPRT"

Question:

Can I get "File Name" in this list? so it creates "SW-File Name@Part1.SLDPRT" (or similar) with an Evaluated Value in this case of "Part1". Typing this in does not seem to work

if so how?

Where does SW get this drop down list from?

I know all about \$PRP:"SW-File Name" This will not work for me

Reason:

When inserting this part into another (inserting Part1 into Part2) and bringing forward a Custom Property of \$PRP:"SW-File Name" this returns "Part2" when I want it to return the Value "Part 1"

Properties that use the drop down will bring forward (example)"SW-Mass@Part1.SLDPRT" and will return the correct mass from Part1.

Cheers

BenM

SolidworksParts And Features