Nirmal,
Use lots of caution here. A 220 (W220) is not a rare car and it is very, very expensive to repair down the road. Impact like that which was sustained by yours may, imo, haunt you down the road even if you get the car back to looking perfect. There are control modules for control modules for control modules that have undergone shock they were never designed to sustain. Every fastener from the rear bumper to the front has been subject to stress that can surface, down the road, in squeaks and rattles.
For my money I would move on and up. If you are bent on driving a W220 or W211 my suggestion would be look for a pristine example and spend the "premium" you would have to pay to keep your wrecked car on one that has not been damaged.
Just my $.02
g