Part of what he wants to do sounds like including a table definition, which would be config, not code.
I got the impression that he mostly wanted to include text/html and some external code (e.g. functions). I saw the part about using do for config purposes in that other page that I linked to, which is why I said "in general" don't use it. I assumed that if he read the node that he'd get the idea. I've seen do abused too many times (post perl 4) to just say "here's how do works, go ahead and use it!" It's better to give context and better alternatives when possible.