You could set up an operator emergency number in number analysis, calls to this number overide all other calls.
You can do this with
NANSI:NUMTYP=OE,NUMSE=XXXX; /*XXXX being your choice of number */
OPCTS:CORG=z,CALT=0,OACC=yyyy; /* z being number of new call origin group, yyyy being common operator number, you can check existing call origin groups with OPCTP:CORG=ALL; */
OPCGS:CORG=z,DIR=
/* w
individual operator number */
e.g.
NANSI:NUMTYP=OE,NUMSE=5555; /* emergency operator number */
OPCTS:CORG=5,CALT=0,OACC=5555; /* call origin group for emergency operator number */
OPCGS:CORG=5,DIR=5400,CHO=1; /* operator 5400 will answer calls in this call origin group */
OPCGS:CORG=5,DIR=5401,CHO=1; /* operator 5401 will answer calls in this call origin group */
In this way when internal callers dial 5555 the next call presented to the operators with number 5400 or 5401 will be this call irrespective of what or how many other calls are in the operator queue.