Mtext Auto Numbering Using A Block?

Has anyone found a way to insert custom shapes or blocks into the standard mtext auto numbering function. Specifically, if I where to have a series of callouts using a # or letter with a circle around it that is supposed to refer to a series of number/ lettered ordered notes. I want to be able to auto number the notes and have that circle around each number.

Currently we just use the same block with the circle around it and move it adjacent to where each note / paragraph begins. This is fine on small projects, but you get a list of 40 notes and then change the wording or remove one and every single block has to be adjusted and is a huge waste of time.

Thanks!