Here is my question : How can i disable the right click menu, but still keep the desktop icons. ( xfce 4.8 / centos 6.3 )

Why ?
I am assigned a project to replace our old recipe : Centos 5.8 / KDE 3.4 / KDEKioskMode , for my company.
The main issue we have : we need to create desktop icons with variables when the user login, in order to launch our business systems. The only for me to do that right now is through the .bash_profile. Now, i need to remove the user ability to right click in the desktop and have a menu popping up.
I cannot use the option to ./configure --disable-desktop-menu , since some users, like admins / root, need this right click.

In other words, i need to deactivate the "right click" action for some users only, and still keep the desktop icons.

Is there anyway for me to do that ?
That would be greatly appreciated, as xfce seems to be a lot lighter than kde.

PS : we have customers that use VNC sessions, with more than 150 users, using xfce is a huge gain in ram usage. The right click issue is the only thing standing in my way...

Thanks !