Quote Originally Posted by georgiboy View Post
Taking that idea further, there could be a hidden sheet that is cleared with a workbook-open event that stored the addresses of the changed cells with their respective old values next to them. Each time the undo macro was run it would work its way backwards through the hidden sheet and put the old values back in the main sheet and then clear the latest entry to the hidden sheet, thus creating a large amount of undo possibilities.

Sorry if I am blabbering
Not blabbering at all. Both of your posts sound like good ideas and I would think are doable. Unfortunately I'm still pretty new to VBA and still learning, so this would be out of my current skillset. I've got my worksheet working exactly how I imagined to to work, but then the thought of the undo option hit me and wondering if it would even be a possibility. It's something that I'm going to have to research more to figure out how to do.