can anyone help me program the immobilizer for my RX 400h?

Immobilizer are programed using Dealer scan tool. Go to your dealer.

Incidentally, I just saw a news report video on Youtube about some car thieves use stolen dealership scan tool to disable engine immobilizer to steal the car.

That answer the question how a thief can steal my friend's new Toyota within a few minutes while he watched incredibly from second floor window. He doesn't have a gun in the house.