Find MAC adress in DHCP server and play sound

Hi, please help me with some script thing. I need a script, which find specific MAC address in DHCP server leases and play sound. You know it’s need to notify us when our manager incoming to our office.

like this?

:if ([/ip dhcp-server lease find where mac-address="11:22:33:44:55:66"]!="") do={beep frequency=4000 length=1s;}

Awesome thx! And now i create a sheduler to repeat this script every 5 min ))