Creating a dot-matrix/"scoreboard" text pattern

I'm stumped.

I need to create a bunch (100+) of signs that will have a dot-matrix style pattern to the text.

The desired end-result is something like this:

I started by creating the field of dots, and then outlining the character on top:

That's where I'm getting stumped. What I need is a way to select all the dots underneath the character that are fully within the character's boundary. If I try doing a simple clipping mask, the problem is the dots on the edges are cut off:

That's not the look I want.

I could go through and clean these characters up by hand, but that would be extremely laborious given the amount of work I have in front of me.

I also thought about creating a new font, but that introduces a whole other set of problems...mainly that my output requirements have lots of different type sizes, but all the dots have to be the same size.

Any ideas? Thanks!