Perhaps I'm confused about how it works...
From the mIRC help:
$regex([name], text, re)
Returns N, the number of strings in text that matched the regular expression.
Am I correct if I state for example, that $regex(test,@@@@,/\@/) should return 4 instead of 1? Would someone care to offer some insight as to whether what the mIRC help file states is true, and if so elaborate/clarify? It is either incorrect (and a bug needs to be filed) or I have misunderstood the help documents (and it should be clarified).