We used to have function to do this. In fact, in the very first version of eaDocX, before it was even called eaDocX, it used to do this, but it made documents really hard to read, as every use of the term was hyperlinked…
…and I never worked-out a way to make only the first usage of the term get a highlight, but if it’s something you feel strongly about, I can add it to the backlog.
It’ll be a while though, as I’m in the middle of the next Model Expert release 🙁