Or just grab any text editor such as http://www.notetab.com which has a freeware version and you can load in your pages and do a search and replace. No programming necessary as deaning said. I can load in about 60-70 pages at a time and just replace with a couple of clicks. Keeps the criteria when I load in the next bunch of pages.
Of course you could also just use the good old Windows search facility if you maintain a local copy of your site. At least it would identify the pages.