Marlin config: external temp. controller

Hi,

I am making a huge size 3d printer and plan to use Marlin firmware (I have it on couple of made-by-me printers and I love it).
I also plan to use standalone PID Temperature controller+K Couple+SSR setup for my pellet extruder-hotend.
What I need is Marlin to ignore hotend temperature control. If you can quickly direct me (before I spend a days to find it), if there is a way to do it except a DUMMY_THERMISTOR? and what happens, when I put 0 for TEMP-SENSOR?

Thank you,
Z

Nobody?