I currently have

John A Doe Sr.

I want John A in Column A and Doe in Column B. I have attempted to do the
split by:
Duplicating the entire full name in two columns. In the first column I
edit/replace by using the <space* command replacing with a blank and the
first name is what is left. However, it does not allow me to
<space*<space* to gather the middle initial as well.

What else can I do in order to have the First Name and Middle initial in
Column A and Last Name and possible suffix in Column B