Restrict /fill command built blocks to regions

I want to allow some of my users to use the fill command, so that the /fill blocks only appear in their own region, not outside of it. The problem is that if the person has the permission to use the fill command in a certain region, he can use it all over the map, outside of its own defined land, even when WorldGuard has build deny in the __global__ region. Is there any command or plugin that denies placing of blocks through commands outside of an owned region?

Thank you. I found a way to sort of solve the problem. Basically one has to give permissions to use the wand of worldedit to copy things by clicking on them with the axe only. Then one has to build 6 regions around the users region with worldguard and set them to deny him any entry. This way, he cant move above the 256 block limit nor under the earth, neither to the west, east, south or north. Now the user will be able to use the wand freely inside of his own region and copy with it whatever he wants, but because he can't move outside of his own zone, he will be unable to use the wand anywhere else.