If you've written it in VBA then rewriting in Perl should be a snap! Perl has much better, well everything really, than VBA, but especially string manipulation, control structures and data structures. You'll find Perl is much closer to C++ in many ways than to VBA.

As I said earlier, hashes are the key. Think STL's map class.

For standard sorts of stuff Perl is very portable. For what you have described so far you should be able to move your *nix script to a Windows box unchanged. Note that Perl will even "do the right thing" with native line endings so on *nix it uses line feeds and on Windows carriage return line feed pairs when reading and writing files by default. A \n used in regular expressions and string turns into the correct thing for the native OS.

I suggest you whip up some code than come back for a little criticism. Oh, and always use strictures (use strict; use warnings; - see The strictures, according to Seuss) ;).