I have no scripting knowledge really, but as I'm thinking about it right now, it shouldn't be too challenging...?
There should be some display bitmap for the Hero's Name somewhere in the script. If we have a string next to that that's based on the hero's variable level, then things will be nice and dandy right? We can have level averages and different colors with if conditions and all that.
...Though, saying the difficulty of something, or giving a possible general theory of how to do it, coming from me would probably be close to zilch in credibility. ;a;
Oh well, good luck...!