I would recommend using the built in security level system: Assign the override pushbutton a security level sufficiently high- say 8 or 9 (at my site 10 is for developers only). Then each user has a login name, password, and security level. Only users with a security level at or greater than the override pushbutton security level can depress the button. With this method the event logging system can also track who pushed the button when.
Just one idea- there are many, many different ways to do the same thing with Lookout.
Regards,
Tommy Scharmann