Auto-numbering - predetermine number of characters used

I’ve been using auto-numbering at compile <$n> quite a bit lately. Works great. But I wonder if there could be an option to preset the number of characters used.

Say I’m outputting something that I know will have ~350 auto generated numbers. It’d like to be able to do it so that the lower numbers get a leading zero or two so that all the numbers will be the same number of digits.

Maybe something like <$n999> or <$n9999>to always output a three or four digit number respectively.

I’m using the autonumbering to generate index codes in the format ##XX-<$n> Where:

is the character string I’m using for Import and Split

XX is the current document number (these numbers I’m entering manually in the compile replacement.)
And then the auto-number.

I just think it’d work better overall if those could be a consistent length

Not entirely unrelated secondary request:

Import and split is awesome, but just due to the nature of my documents the titles of the resulting binder documents can be all over the place in terms of length. I wonder if it would be possible to constrain the number of characters used in the new document titles.

Maybe an option in the Import & Split dialog to use first XX characters as document title.