Hi, I have Purchase Order module 3.12 and Zen Cart 1.3.9h

I am struggling for a way to add total order weight and total order value to the .pdf P.O. that this mod can send by email. And I would really appreciate some help with this. The data for these two things cannot be far away from the product model and quantity data that this .pdf already contains concerning a single Purchase order.

Please, Stuart, Linda anyone who knows?