Good morning, and thank you for the code. It is not working right.
Are you assuming that there are 3 different fields called Lastname, Firstname, and Middlename?
There is only one field called Rater_Name, which should have a last name, first name, and middle name entered into it. This Rater_Name entered should concatenate into an initial field called RaterInitial.
I was thinking that since there are no distinct fields, that a script that will concatenate the first character of any words entered into the Rater_Name field after any space or comma could work, but I do not know how the script will look like.