Extracting substrings using regex

Hi,

I have written this code to loop over a range with strings to extract a certain code in each string, which will be in CAPS and followed by 1 or 2 digits using regex. The problem is it is quite slow for the range I am working with. So I figured my code might be inefficient. May you kindly assist in ways I can speed it up. I have attached a sample.
Thanks