OsCommerce Tax Help

I installed the following contribution to my OsCommerce store: City Tax Rate Hack for MS1 (<[login to view URL],1240>) It works fine, and it is a very simple contribution that is used to calculate city tax as well as state tax. However, this contribution is based on the customer's billing address and here in Colorado it needs to be based on the shipping address by law. So basically I am looking for someone who may have an idea on how to change this contribution (or make a new one similar) based on the ship to address rather than the bill to address. Sounds simple to me but I am not a confident coder, so if anyone has any ideas and is willing to give this a shot, please let me know. Thanks! ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform This needs to work on OsCommerce version 2.2