Hmmm, but shouldn't there be some way to just make a copy of the file, put in a container and tell the AI, scan the environment, do nothing except watch what the excel sheet does and record it, then determine how to create an identical sandbox containing the same outputs and feedback. Then see if the sheet works in that sandbox. If it does, then debug it until you get identical behavior out of a new program. Then have a week/month of dry runs just copying the inputs from the real world to it and capturing its output to compare to the dll. Do that for long enough and you should have a drag and drop solution right?

I'm not saying it's easy, or worth anyone's time, but it should be possible right?