Sales Tax report by zip code

I am trying to figure out how to create a report that will show my sales tax by zip code or city.  Either by adding a column to the Sale Tax Report already in Sage 100 ERP Accounts Receivable or by creating a new report.  Does anyone have any suggestions?  We are a small company and only report sales tax in 2 states.  The tax automation software is costly and not worth the investment.  Just trying to make things a little easier when reporting each month.