Initially I thought I'd need to rebind the regular expression at will to hop around to different array elements. I think instead... maybe when the engine isn't doing a normal 1-d regex that it'd need to run custom code that isn't regex at all to follow the data around. So this brings up the question - I've not seen a Regex tokenizer around (not that I've looked that hard either). Maybe with one of those an a controlling function you could jump around, test atoms and when possible use the normal regex engine

Do you need DFA or NFA regexes to do this? You know that Perl regexes are regex directed not string directed dont' you? In fact, I am just saying something. I still dont know what in the world you want to do. I'm just grabbing at straws and brainstorming.

Carter's compass: I know I'm on the right track when by deleting something, I'm adding functionality