Sumif with Find and Mid

Your June 8,2000 article “Using Excel’s Find and Mid to extract a substring when you don’t know the start point” is perfect for my application…I now need to combine it with a sumif statement, if possible. Let’s say that I would need to sum sales for all products with the code B3? The article found 2 instances of the code B3 after the dash, for example. (Yes, I know I can easily insert column for the resulting code, but the spreadsheet is getting unruly and I want to minimize adding extra columns). Thanks!