Well, it may or may not be “what the OP really wants,” but it seems to work, and in the end, IMHO, that’s what really matters most.

We have a special subforum for “regex tricks,” and it's called:   “Obfuscated Code.” ;-)

Seriously... the most important thing is that the code, whatever it is, is easy to understand, is reasonably efficient (not that such things really matter too much anymore), and is easily maintained.   When (not “if”) the requirements change (again), it ought to be the work of five minutes or less to change the code, and to be utterly confident that it works.   Anything more “clever” than that is always regrettable.