Refill point for a top mounted radiator? How? Fractal Design North XL case.

Update 1: Hrm, doesn't seem like the North XL case is that good for water cooling, not enough space I think. I only bought it for air cooling to be honest. With push fans at a front radiator, cleaning will require removing all 3 140 mm fans each time I think. With pull config, that eats up 25mm of space where radiators will go. I guess a 280 rad w. 2 fans instead of a 360 rad w. 3 fans would work on top.

Update 2: I guess 280 rad on top (40mm), and 420 rad at front (40mm), might work.

Lets say you have two radiators, one to the front of the case standing vertically, and one on top hanging horizontally.

Then, there's this hole on top in the computer case for refilling water into the loop. How does such a top side re-filling point mix with a top mounted radiator that is horizontal?

Q1: Does the re-filling tube go into the top mounted radiator in the third hole, or any other way to do this well?

Q2: Can you have a reservoir with filling port below the top mounted radiator?

I should point out that I don't know much about watercooling, which is why I am asking this.

I think the distance between the hole in the case on top, to the hole in the horizontal radiator on top, wouldn't be more than maybe 2 cm or so. The hole in the case is covered on top with a mesh, so apparently a screw lid would have to go inside the mesh that lie on the very top side.