Touch screen with no keyboard or mouse

I am running an 'all-in-one' touch screen PC as a kiosk terminal for a sports club court booking system. It is set up as far as possible without extra software to be locked down so the IE8 application starts on boot and runs full screen. The physical keyboard and mouse are removed and the mouse driver is disabled on startup.
The application does require text input and where a text field is touched the on screen keyboard is displayed.
The on-screen keyboard does not have a control key so how can SecureLockdown be de-activated if necessary for any maintenance work? Would it be by attaching the keyboard and mouse during boot so the control+S can be input?

Currently, the quickest way would be to use a USB keyboard/mouse. You would not need to restart the computer if you used USB. We may add the ability to modify the Secure Lockdown invoke key sequence in a future revision.