Filter Field for only Letters

[briankuhlmann]

I have a field with Account Numbers. Some are only letters (A-Z), some are only numbers and some are a mix of letters and numbers.

Is there a regex_match i could use to identify the accounts with only letters?

Right now I tried this in my filter: REGEX_Match([ARMaster], '^[\d\-\.\,]+') 

It separates the just numbers accounts but leaves the just letters and mixed accounts together. I am trying isolate the accounts that are strictly A-Z , no numbers.

[binu_acs]

@briankuhlmann 

REGEX_Match([AccountNumber], "^[A-Za-z]+$")