Connect external hall effect sensor to a door sensor?

Do anyone know how to connect an external hall effect sensor to a door sensor like Fibaro FGK-10x or similar? is it possible? FGK-10x has an input for dry contacts or temperature sensor. Will it work with an external hall effect sensor as well?
I need a sensor to check that a doorlock is really locked. There is only room for very small component like a hall effect sensor. Hall effect sensor is prefereable due to low supply current. Components must be battery powered.
Use of reed switch is an option, but I believe this is unreliable.
Does it exist other z wave devices where it is posible to connect a hall effect sensor?
Thanks for any inputs

You could try hacking an Iris 3320-L Contact Sensor. It actually uses a Hall Effect sensor chip instead of a reed switch.