Lights via receiver controlled switch, joystick mapping

Hi everyone,
I am trying to use the buttons on my joystick to operate Lights and smoke on my rover/boat. I can use the extra channels to operate the lights etc via the X & Y axis on the Joystick but that leaves me on channel short. I have 7 extra buttons on my joystick so I was hoping to map the channels to the buttons but can figure out how to do it.
I’m using APM 2.6, MP, Turnigy receiver servo switches, 3DR radio, Thrustmaster T-Flight joystick.
I will also post this on the new site.
Thanks in advance
RS