I'm trying to retrofit unit tests onto my codebase, and I've stumbled across something I'm not sure how to resolve. Within the program, a business object adds a new record, and later saves it when done, and I can test that easily. I can't easily test what's in between - the user entering data and textboxes updating their controlsources.

What's the best/easiest way to get test data into a record? Given that the number of fields adds up quickly, rather than using a function with umpteen parameters, I started looking at a parameter object. That only seems to move the problem down one level of abstraction - how do I fill in the parameter object values?