How to get a horse to lunge?

ive lunged horses for many years but have never had to teach them how to do so. if i hook a lunge line to him he just stands there and stares at me lol. i do not have access to a round pen or anything like that. we have a 50-60 foot corral but the shelter is attached ( alright tried he goes and hides in there. hes a ottb and knows his walk and trot commands but he just freezes when i put the lunge line on him.