Okay, that sounds more like when a creep was killed created another one after x seconds passed at the same spot he entered the world. I assume you use GUI in jass mod (default). In that case call CreateNeutralHostile()
won't help you, because it would create all preplaced creeps on the map regardless if they are dead or not.
To be able to create them were they entered the world you need to know for each creep where it started.