This isn't going to be much help, but regular expressions are always going to look like line noise to someone who doesn't grok them.

If you're writing for someone with little Perl knowledge, then all you can do is

1. Write clean tight code. (which you have)
2. Document it (which you were about to), even if it's on a line by line basis.

_rant_on_
I'm personally getting to the stage where I am p**d off about pandering to developpers who want to use a programming language without making an effort to learn, not just the syntax, but also the idioms. If regular expressions are part of the language, then use them as they were meant to be used. If conditional statement modifiers are there, then what's the point of pretending that they aren't?
_rant_off_

Just about the only thing that you can do is to teach the perl-deprived; and one of the most immediate ways to do that is to fully document the code.

Just my two centimes.

-- 
I knock my pate and fancy wit will come
Knock as I please, there's no one at home
      a pontiff paraphrased
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