Replaced steering/ignition column anti theft light is still blinking

My car was broke in to and the ignition was torn up. I replaced the steering column. While I was in the process of getting the car repaired the original key the went to the old ignition and unlocked the door was lost. The anti theft light is still blinking. I have looked on line at ways to reset this and it appears one of the steps involve locking the car with the key from the out side. I was hoping you could shed some light on this and let me know what to do.