Mob spawning based on block Y stat.

Well.. ehhh, the title is pretty straight forward
I need a plugin that allows me to spawn monsters only on certain Y coords.
For instance,
skeletons = Layer 1 - 100
Zombie = Layer 1 - 255
Bat = Layer 150 - 255.

As for a config,
Something like shown above would be great!
As long as it allows me to set the high levels I'll be happy x3

Commands,
Reload

Permissions
Reload.

If you can create the commands to edit the config in-game. That would be great. But we dont really need it

Thank you so much for your time!
Syra