I very nearly reroasted the old "dynamic loading" chestnut:
dynamic module loading. I was in the process of composing my question when I did remember to search perlmonks and I came upon that thread. I read through it all and still I was puzzled: "Why had no one written the 100 or so lines of coded needed (including docs) to upload a suitable module to CPAN?" Then I found it:
UNIVERSAL::require. And that thread was written in 2003 and the module in 2005 which explains why it was not suggested as the solution.