well if it's not a complicated object or if the object doesn't move a whole lot you can just create an animated mask layer in your compositing program to ensure the church shows and the characters 'go behind it'...

otherwise the 'black hole matte' is actually a material. it's called the 'use background shader' and when applied looks green in the viewport. it doesn't show up in renders but shows up in alpha channels, and it still receives shadows from the other objects in the scene.