[10.5] Add Domain Users to Staff group?

I have about 100 macs bound to a 2008 Active Directory. All works well but one thing would make my life so much easier permissons-wise. And that would be to add the Domain Users group to the Staff group. Does anyone have any suggestions? Have have been reading man-pages for dseditgroup and dscl and well I havent got my head around it yet. So just to be lazy and to get some really good advice I turn to you.