avoid fullscreen window

[9acca9]

Hi.
There is a way to do this?
I want to constrict the windows to a place even if the app is set to "fullscreen". (im not talking about maximize, instead fullscreen)
Thanks

Edit:
i try this code but nothing happen when i put firefox in fullscreen

if get_window_fullscreen()==true then
    debug_print("LOWERING WINDOW " .. get_window_name())
    set_window_above(false)
    set_window_below(true)
end

What i want is to constrict the app to some part of the screen