Conditional formatting for a cell that contains a single numeric text character

Question

How do I set conditional formatting for a cell that contains a single digit as text, not as a number!

There seems to be a maximum number of conditions which can be assigned to a cell. And, conditional criteria don't understand an 'OR' relationship. Does anyone know a solution to this dilemma other than writing an event function?

Answer 1

I suspect you asked in the context of 'old' Google Docs - switch to new Google Sheets and Conditional formatting now offers Custom formula is. So rather 'a cheat' but please there try something like:

=and(len(A1)=1;left(A1;1)>char(47);left(A1;1)<char(58))