How to define an object in another layer?

I have a second scene and using scene2.objects["obj"] isn't working. The object is is another layer, and I cannot figure out how to define it. I've defined "scene2," and there is no problem with that. How do I define objects in different layers?

Layers are properties of the object see this snippet:

import bpy

# create layers vector with only one layer enabled
def layers(l):
all = [False]*20
all[l]=True
return all

o = bpy.data.objects["Cube"]
# set object to layer 2 only (layers from 0..19)
o.layers = layers(2)

# lookup scene by name
scene = bpy.data.scenes["Scene2"]