Trying to Walk my Cat

I don't normally write about my cats on my blog but I am a cat lover. Sprinkles is my all black male cat that I brought home after a shift in the cat room a few months ago. Ever since the weather has gotten warmer Sprinkles had been dying to go outside. One day he finally slipped out the front door. I hoped he would come back quickly but he got lost and was gone for about three weeks. After searching all over Victor for him I finally heard someone might be taking care of him. I passed out fliers and got a call the next day. I was so happy to hear Sprinkles was safe. But now hes home and he still wants to go out. So what do I do? How do I teach him to go outside and come back to his house? Today I put Bailey's harness on him and tried to walk him around the house. That didn't go great but we spent a few minutes outside. I will try this again a few times this week and hopefully it will help him get his bearings.