A way to change a tile in a text HUD element?

I've tried a few different ways, but all of the built in MACROs I've tried don't seem to be able to do the trick. What is needed to be able to change a specific character in a text element in the HUD?

I'm attempting to change "A.M." to "P.M.". I was hoping that 'SetTileToChange' along with the 'UpdateHud' MACRO would work, but nope. Right now I'm at a loss.

A workaround... If you have free hud variables ... you could use one hud variable for dealing with your "A" or "P" tile.... for example, using a vartype tile empty / full "A" or "P" setting the variable value to 0 or 1....?