Sure, here's one off the top of my head.
What's making putting it in hard to do is the friction of the leading bottom of edge of the steel hitting the oven rack. You can amend that friction a couple ways, but the easiest thing to do is smooth the steel and oil the rack. Still not going to do much for your back, I'm afraid, but it will make the process a lot faster.
If you have a metal-finishing file, take down the 90 angle to more of a rounded edge.
Take a paper towel, put some oil on it and wet at least the front of the rack.
To save your back some pain, make a 2x4 box end (use 4 pcs of 2x4) a little higher than the rack. This is just something to rest the steel on for a moment. The box should sit on your oven door hinge area so that you can put the middle of the steel on it, then tip it forward and have it slide right in. Just a little helper.
Well, you know this still doesn't help you get the steel from wherever you keep it, and walk it to the oven. If I were you, I would definitely go with the lift table. It will make it easy to put the steel back in, and gives you a rolling place to keep it.
Want some motors? You know, you're not far off thinking about the motorized track, Mr. Taylor. Originally I was thinking a mini forklift with electric winches.