I'm looking to use Perl to create (a batch file? .exe?) to find and replace all instances of a specific string, within any text files I point it at

I generally prefer to be able to teach myself, researching and finding the commands I need and whatnot, but so far, it all seems pretty overwhelming

I've just downloaded ActivePerl 5.14.2 and not sure what the heck I'm doing

and what's with all the Captcha fields at every turn? will that go away once I verify my account further, somehow?