Hi, I'm still learning so probably my question could sound silly:
If I want a character behind a prop and part of the body remains behind the prop and the hands and arms, for example, are placed in front of the prop itself, how can this be managed?
Is there a way to make layers interact between characters and props or layers work only on the character itself? 
Please address me to the right hint.
Thanks.

Max (Italy)

Here's one way to do it: Firstly, animate the character behind the prop as you would do it. Duplicate the already animated character by holding down ctrl and moving the mouse. This is a copy, so it will have all the animation data as the original. Place this duplicate on the exact position as the original, but move it in front of the prop on the Z-axis. Turn all the unneded layers to empty on the duplicate (in your case, only arms and hands remain). Since this is 2D, and the duplicate is on the exact position as the original, it will create the illusion that body is behind the prop, but arms and hands are in front. Credits goes to Garry Pye for the trick

Thank very much. Will try it.