There are as many ways to do what you are asking (put the center into emergency) as there are Call Centers, but here are the ones I've had the best luck with.
1.) Global Variable: Use a Global variable type Boolean, set the value to TRUE (Emergency) via a browser.
2.) Wild Call Variable: Use a variable type Integer, set the value from 0 to 1 with a script...
IF CLID = my-cel-phone
THEN
READVAR x_Counter_wcv
ASSIGN (1 + Emergency_wcv) TO Emergency_wcv
SAVEVAR
END IF
You can also use a collect digits to do this as well so that you can turn it on and off. You can have another varialbe for the approaved CLID's that can set the value.
3.) HDX: Use HDX to connect to a database where the "state" of the center is stored, and turned on or off.