I am currently using the index match formula below:
I would like to modify it to match only the first 4 characters of the text string in A2 instead of the entire text string in the cell. The first 4 characters are a mix of alpha-numeric characters, and always have an underscore following them. If there is no match, I would like the result to say "Not in book". See examples below of text string:
I've also included a sample file to illustrate what I'm looking for.