PHP & ?? How to edit a "Message catalog binary file?" or "GNU Gettext..."

[ZiNgA BuRgA]

What the hell are you doing?

Notepad and co aren't designed to edit binary files, they're designed for text.  Hex editors are better suited for binary files.
But I have no idea what file you're trying to edit and where you got it from.  It may be visible as plaintext, or even as encoded (ie UCS-2) plaintext, but there's no guarantee.  For example, a simple layer of compression will stuff up your attempts.
But you can try a search with a hex editor if you wish though.