The FTB Forum is now read-only, and is here as an archive.
To participate in our community discussions, please join our Discord! https://ftb.team/discord
You could use essentials, which allows for you to do exactly what you want.
Whether this feature is available in 1.2 though, I'm not sure. (I'm assuming you are on Minecraft 1.2.5 since I see EE2 items on that config).