HAND CARRY BAG, LOST AT TERMINAL 3, BUT FOUND IN LOST AND FOUND IN BEIJING AIRPORT

On 30 may i lost my dark brown small bag at security check counter at terminal 3(CA991,AIR CHINA FLIGHT)with following things in it------
1.Apple i- phone ,3GS with ear phone and charger. (2)Samsung cell phone with ear phone and charger.
3.LOCKER safe vault keys. (4)Watch ,Tommy Filger brand(5)BLOOD sugar testing machine.
I HAVE A QUESTION that status is Returning Passenger of Air China and coming back on 1APRIL ,2014,SO i will be able to claim my belongings from lost and found office at terminal 3 ,Capital International Airport.I want to know the period validity to claim the lost stuff.Further can the lost and found office may be nice and good to send my stuff by POST/COURIER SERVICE.NEED YOUR HELP,THANKS.