Keyless entry panic button

I have a 1999 Dually Diesel with keyless remote entry. The original remote only has 2 buttons. The new one I just bought from GM has 4 buttons and one of them is a panic button. I'm wondering what if anything I can do to make the panic button work on this remote? I got the answer on here to make the transmitter work on my truck but the panic button doesn't work. Thanks for any help you can give me.