I'm using Illustrator CS3 and I have two objects.
How can I get one part of the object on top of another object and the other part of it under the other object?
I'm probably wrong but offhand you cant do it so simply. You have two options.
1/ Duplicate the object that will sandwhich the other... let's call them Object 1 and Object 2 respectively... into a separate layer or sub-layer
2/ So, Object 1 is now duplicated. Move one instance so that it is on top of Object 2
3/ Creating clipping masks, block out the relevant bits of Object 1 and you're done
The same first steps as in Option 1, then:
1/ Delete the parts of Object 1 upper and Object 1 lower that you don't want to show.
In some cases, depending on what you're trying to do, one of the Object 1 avatars can remain intact...