I'm trying to formulate a data validation code in Google Sheets for a simple 6-letter string - any 3 capital letters and any 3 lowercase letters. I believe I should be using the RegexMatch function. Here's what I tried:
=RegexMatch("[A-Z][A-Z][A-Z]\\[a-z][a-z][a-z]")
But when I try to type AAAaaa
in the cell it rejects it.