[GTALUG] Ad Hoc network Question On Ubuntu

I have some small devices that usually connect to a WIFI router and send data to my laptop which is also connected to that router. I thought I would try setting up an ad hoc network from my laptop without the router and have the devices connect directly to my laptop. I set up the network with the same SSID and password as the router. The devices are programmed to send to a specific IP address that my laptop is set to when on the router. The problem I'm having is when I set up the ad hoc network I don't see any way to set the IP address of my laptop on that ad hoc network. Is what I'm trying to do possible. Is there a way to set the IP address for the ad hoc network via the command line? Thanks for any tips. Jim