Hello Alberto,

You should make the whole area of controls unvisible using the parameter Visible="False" in the ascx. But this method does not allow anyone to access in this options in the future.
What you should feel better is to rebuild the event module and set this parameter throught the codeBehind. Simply check the user-group and set the visible parameter false or true (Admin group, visible=true, else, visible=false.).

Seb