Ah - now I see, you want to do some "structured" parameters. No, I'm not aware of something like that, but if you go for dots as delimiters, [...]
Unfortunately (fortunately ;) this is perl, so we have to have multiple delimiters to be able to support both hashes and arrays. That makes things a little more complicated (not to mention that pesky error checking).
Thanks to you (and Anonymous below) for the code drops. I wasn't really looking for "help me write this code" so much as "help me find the module that surely already exists to do it", but I'm continually impressed at the willingness of the Monks to go that extra mile.
Sadly, none of us were successful at finding the existing module. I'm still shocked by that. Left me no choice but to go solve it.
So I did, and the next time someone asks, we can tell them CGI::Struct.
Annoyingly, I just got a mail about a test failure on 5.6.2. At a glance, it looks like it's just a problem 5.6 has with the test, not an actual code issue. Hrumph. Now I need to decide whether I want to fight through a 5.6 install somewhere to fix it...