I've seen a couple questions on here approaching what I want, but nothing quite there.

So I'm making drawing templates for my company as we transition to Solidworks, most of what we do is sheet metal, and our laser operators have asked us to put a total burn length on the drawings.

I'd like to do this in a single field of the titleblock, which precludes adding an entire BOM table, the easiest way I've seen of doing this, and I'd also like it to be robust enough to handle it when the Sheet Metal body doesn't have the same name (Some of our parts have Sheet<1>, others Sheet<2>, etc), and I'm hoping to find a solution robust enough to handle this, but i don't need it to handle more than one sheet metal body.

So the TL;DR question is: Is there a way of making a field in a drawing that pulls the Outer and Inner Cutting Lengths from the first sheet metal body of a part, adds them together, and can be linked to a single Note, and can be entirely contained in the part and drawing templates so we don't have to do something every time a part is created?