bulk search and replace for multiple lines?

Is anyone aware of a free, preferably lightweight application that can do a search and replace for multiple lines for multiple files?

For example, I have a PHP script that has maybe 20 lines of code that I want to replace with just one line of code - "<?php include("footer.php"); ?>", and I have about 100 files that need this change.

I have the program "Programmers Notepad 2" that has a bulk search and replace feature, but it seems to me that you cannot replace more than one line. It gives you the option of using regular expressions, but I know nothing about them and if they would be the solution or not.

If you are comfortable with *nix, look into the program "sed"

You just run that through a for loop for all the files should be replaced.

Dreamweaver's built-in find-and-replace tool is the best solution that I know of. You can make global changes to hundreds or thousands of files in one shot. DW isn't free of course, but there's a free trial.

There's also this tool, which I haven't used, but it looks like it would get the job done: