how to edit plists for a group in workgroup manager

hi I am an It technician in a School which has been windows based

Over the summer the school upgraded to a 95% mac network we still have a small windows network as one database would not work on Mac osx server

authenication and user accounts are also provided from the windows server's and also we are using a citrix soution to access windows apps from the macs

140 imacs have been rolled out and we have 2 mac servers with deployment studio apple remote desktop and workgroup manager which was set up with groups and access rights for staff and pupils.(i was not involved in initial setup)

Anyway I am starting to get my head round the mac side of the network but we are having issues where pupils are saving data to the local profiles when they log onto the macs and not the network shares that are allocated to their profile when they log on which means that when they log onto another mac their data is not there i have been asked if its possible to remove all local save area's from the finder and favorites pane's and only leave the pupils allocated network share, desktop and downloads as save locations is there a way the finder and favorites can be edited?

I am assuming that i edit a plist possibly and then replaced the edited one into workgroup manager

any help to point me in the right direction would be much appreciated

regards

Lee