Is it possible to "pre-link" a custom property to a bounding box?

i.e.

We create a lot of assembly based sheet metal parts. On our drawings we combine the bounding box dimensions into one cell. (Cut-Size=Bounding Box height X Bounding Box Width)

Example

Cut_Size = "SW-Bounding Box Width@@@Cut-List-Item1@Part1.SLDPRT" X "SW-Bounding Box Length@@@Cut-List-Item1@Part1.SLDPRT"  = 2'-1 9/16" X 2'-11 1/8"

Is it possible to enter the bounding box formula into the Cut_Size property on our part template so we don't have to add it to every part after it is created? One problem I forsee is the filename will obviously be different for each part.

Thanks