Bert,
Is this the shortcut you're referring to, to lockout your computer when you leave the exam room?
SHORTCUT TO LOCK COMPUTER:
GO TO DESKTOP->RIGHT CLICK->PRESS NEW SHORTCUT-> AND THEN PASTE THE COMMAND,
%windir%\system32\rundll32.exe user32.dll,LockWorkStation
then right click on the file created and click Properties
go to shortcut key, click on this line and press any key(e.g. F3) as the key to automatically lock out computer when pressed
