A custom webpage would probably be easier to use for children with special needs as well as you can use larger pictures / different colours.
I use this to save and restore the desktop icon locations. Usually copy the 2 program files into windows folder on master pc before using wds and use a script either at logon or in startup folder to restore icon locations from file on server.
Hope this helps
Theres a little app that i used before called desklock or something like that. It can run from a network share with a little tweaking and sits in the sys tray. If you hide the sys tray they can not disable it then.
Worked pretty well for the little time i used it.