Bridging spending categories to IMPLAN Commodity S

Hello. I have a question regarding how to bridge spending categories to IMPLAN commodity sectors. I have survey data that contains spending information by categories, which I would like to use to customize the production function. I realize that spending categories need to be mapped to IMPLAN commodity sectors first (Customize>Industry Production). I understand that IMPLAN industry sectors can be found via the "Sector Search" option. How about commodity sectors? For example, I'm not sure to which commodity sector I should assign stumpage. My project is about commercial logging. thanking you in advance, Daniel Lee, Ph.D.