[6.3] Assigning "shutdown" to eg. Syst?

[Gilles]

Hello

I'd like to make it easier for my dad to shutdown a server. Instead of
having him plug a keyboard, log on as root (with a complicated
password) and finally type "shutdown -h now", is it possible to assign
this command to some unused key like eg. Syst? Even better, send this
command only if the key is hit eg. three times within 2 seconds?

Thank you.