Forums Scripts & Popups on HOTLINK - Partial word match?

mIRC succeccfully recognises URLs when the protocol is connected to another word, e.g. "https://google.com" is hover-able and click-able in "wordhttps://google.com". I cannot figure out how to recreate this behaviour, however.

As an example, I would like to match a single character inside a word. "e" should act as a hotlink in the word "hello", but "h" and "llo" should not. Is this possible?

A regex match captures the character easily, but the on HOTLINK event always matches the entire word, regardless.