Hi Dr. Ludwig Reinhard,
Thank you for taking the time to respond. There is nothing wrong with the tax calculation system. I work for a tax company and one of our clients using D3fo as their ERP wants to integrate with our tax engine. They want all types of tax, certificate filing, auditing, etc to be handled by our system. I just need to send calls out to our tax engine when the tax calculate method is called for d3fo instead(as a first step, this will be long process adding all the other functionality). Then upon returning tax information, populate tables accordingly. There are a few paths that seem like a good way to integrate, and I am looking for advice as to which road I should take. As I mentioned, I'd like to avoid overlaying existing code, in case the client has made changes to the code themselves that they want to keep.