Well, a dirty way could be this:
Lock the layer XL or better turn it off. Select all the objects on the screen and do a COPYBASE. Enter #0,0,0 as origin. Now delete the objects and press CTR+V to bring them back from the clipbord. When prompted for the insertion point specify the same #0,0,0.
All these objects are new in the drawing so are in the front of the existing ones -those plased on the layer XL.
Just my oppinion