[CentOS] Persistent desktop icons ?

Hi,

Is it possible to configure persistent desktop icons, e. g. shortcuts 
that users can't delete ? On most of my client desktops, I have some 
home-made shortcuts, like here for example :

http://www.microlinux.fr/configurations.html

The shortcut on the lower left corner of the screen launches the public 
library management system.

Most of the users are quite computer-illiterate, and more often than 
not, they tend to erase these shortcuts (and then call me panic-stricken 
at 07:00 in the morning :oD).

To configure the shortcuts themselves, I just edit a .desktop file by 
hand. I tried various combinations of chown and chmod, but to no avail. 
Even if there are minimum access rights, the thing can still be erased 
with a right click.

Now I vaguely remember that a standard openSUSE install has something 
like persistent desktop shortcuts (for the SUSE help center or something 
like that), and I wonder: how do they do it ?

Any suggestions ?

Niki