Its possible, you just have to change the text in the world guard config file or whoever ever it is :P
I'm afraid it's not that simple. I'd have to
1. Check that WorldGuard is open source
2. Find that line in the source code (assuming it only appears once)
3. Change that line without using ' or " or \ or who knows what else
4. Recompile the .jar file (something I've never done before since I'm not a coder)
5. Install it and pray.