Asterisk & BLF & 7961

I know this has been asked before but all the posts are too old for use. I am trying to use all Cisco 7961 phones and have parking lot blf on 3 of the line buttons. I would like for someone to place a caller in a parking lot using the attendant, once the caller is parked I would like the line light on everyone phone (around 15) in the company to light up for that parking spot.

Most information on this is for asterisk 1.4 or 1.6 not 2 or 3, thats why I am making a new thread.