i just wanna tell about a working plugin for Gedit to use Regular Expressions. You can find it here: https://live.gnome.org/Gedit/Plugins...-gedit3.tar.gz
I extracted the archive to ~/.local/share/gedit/plugins
After I opend Gedit,
went to Edit -> Preferenses
choosed the Plugins tab
and checked regex-replace
you will find the new option in the Search menu on the top of the window.
Im running wheezy 64bit.