The project is a calculator tool. I'm trying to idiot proof it for users. In the above macro I'd like to set the acceptable range for pasting csv data, in this case C5:E14, and if the paste is too many columns or too many rows, I'd like it to exit the sub. A rejection notice of some kind would be nice.

It's not critical, but would be great.

I'm still sorting out the suggested IfEmpty function. It looks promising. This is a hobby application. I'm no pro and just doing this in my spare time.