Correct.
But 9000>142,01:142- means that the key is currently programmed. It may have been set up as the prime line. You'll want to select an unused key.
I suggest 95, the answer key (mostly useless, otherwise).
that would go like this:
9000>142,95>CCC
9000>142,95>F1090
The F is vitally important. 1090 would mean, "make this a multiple appearance of extension 1090." F1090 means "make this a feature key, for feature F1090 (headset)."
Be very careful to write down what you do so that you can undo it if you cause GSW (General System Weirdness).
