I'm not sure what you're trying to accomplish with your horse, but if you're just looking for a way to work him on the ground and don't have a lunge line, you can try groundwork. You can do this with a halter & lead rope. The exercises are kind of hard to explain in words, but I can give it a shot.
Exercise 1: Stand in front of your horse, holding onto just the end of the lead rope. Shake the rope, starting easy at first & gradually getting harder until the horse takes a step back. As soon as he/she moves, be quiet and stop shaking. Repeat until there's little to no slack left in lead rope. Then, pull on lead until horse walks to you, releasing pressure once he steps forward.
Exercise 2: Referred to at my barn as "Around the World". Toss the lead rope over your horse's head onto the side opposite of where you're standing, keeping hold of the end, and walk towards your horse's hind end, wrap the lead rope behind his rear & pull until he swings toward you. Be careful, though, & watch out for his behind. (Sorry, I feel like this is the worst description, but it's the best I can think of)
Exercise 3: In a way, like lunging, but not. Send your horse on a circle around you, using the end of the lead rope & swinging it over hand to get him moving. Once he's on the circle, stop twirling. Do this both directions.
Exercise 4: Incorporated with exercise 3, take hand that was holding the end of the lead rope for twirling & grab further up the lead rope, pulling horse's head towards you & grabbing the end of the lead rope with the other hand to twirl it if needed to send horse back on circle. It's basically just changing the direction. You can do this multiple times throughout the exercise.
Exercise 5: Also incorporated with Exercise 3. You do a hind end from the ground. While the horse is on the circle, shorten the lead to about arm's length & walk towards horse's rear end, causing his head to turn and him to move his behind away from you & his back feet to step over.
If anyone can think of any others or describe these better, please feel free to do so!