Perl had $[ (yes, just those two characters) to allow setting of the first array index, but it's a fatal error to put anything but 0 into it now.
Of course, since Perl arrays can be negative subscripted from the last element, you can stand on your head and index the array negatively from the wrong end. -1, -2, -3 etc. Use unshift to put things on the beginning (logical "end") of what you're doing rather than the usual push. Presto, a 1-based array (up to sign, anyway).
You may wish to file this under "stupid, but it works".
People with more time / more need for something that looks professional, would probably be better off writing something that uses tie instead. (Or, yes, yes, a different language entirely, hush now.)