hide object at the render but still reflect

[Eunhyoung]

i read the "Hide Geometry from camera? "

it worked when i applied at the ground floor

but it doesn't work when i applied at the square.

i am working at the elevator industry and i need to render inside the cabin interior (like a box inside)

so i useally open onside wall to render.

but the problem is i have to photoshop to refelcton of the open wall. and it is hard work.

is there any solution? to hide wall but still influance at the reflection?

my colleges use max vray and they just have option.