If you have a workout partner, just have them hold your feet and lift as you walk closer to their body. It's kind of weird, but you could get that to work.

If you have a pull up bar/rig with rings, you could hang your feet in the rings and handstand walk toward the bar. As you progress past the bar the rings will rise higher and you'll be in more of a handstand position.

If you have a squat rack post or type of pole, you could cross your legs and rest them on the post and wall walk toward it. Your feet will slide up the post as you get closer.

I've never tried either of these, so good luck, but they might work.

Send a picture of what your gym looks like. I'm sure somebody could figure something out. I workout in my garage, so I've had to make tons of adaptations to the movements.