That has certainly added much impetus to my thoughts of "really must learn Perl one day". In what has traditionally been a very Windows-centric workplace, it can be difficult to gain acceptance for useful tools :)
I do, of course, have Perl at home, but haven't really had any good reason to learn it.
I think this has ended up taking longer than if I had altered all the files manually. But it's been much more rewarding, less prone to error, I've learnt more about sed awk and regexps, and it's been way beneficial to the whole job satisfaction thing. Hurrah.