Well, I don't know if Excel will be the best tool for this, but I sure had fun making the following program. My vision is that eventually I can create several of these and put them on my class website for the kids to practice their skills. I know there are great practice tools on the web, and I do link to those. My thinking in creating this type of program is that the kids will see what I think is important for them to know.
Anyway, it looks like:
It's interactive and provides hints for the tester. When you open the Excel file, you have to enable the macros in order for it to work. Now I have to figure out how to create my Geometry Proof Excel "quizzes".