In the event when you spawn the sprite, you can assign the UID of the sprite to an instance variable in the spawner object. Then run an event where the spawner object will check if a sprite with that particular UID exists. If it doesn't, spawn a new one and overwrite the old UID.
Edit: Here is a capx -
Notice the For Each condition is important here. If you don't use it, all instances of the spawner objects will be set to the same variable.