help with excel data validation
So I'm working with Excel's data validation and I'm not too great at the custom formula for data validation. Is there any way to require a cell to have at least one number and one letter, in no particular order? For example, HELLO512 or 3H would be allowed but something like 12345 or HELLO would not be allowed. Also! Would there be any way to prohibit all special characters except for underscores? I'm using Excel 2016 if that matters. Thanks
July 4, 2016