If there only a couple of such objects, you can position them off screen so that they cannot be accessed (clicked, trigger accidental collisions, etc) and then recalled and re-positioned by picking them with their UID. You can store their UIDs in a simple array for that.
If there are dozens of them, so that hiding them will probably affect performance, you can do the following:
Using a 2 dimensional array, you can store whichever properties you want for each one of them and when you want to "store" them away, destroy them. When you want to bring any of this objects back, create a new instance and pass it the stored properties.
Note: Don't try to store their UIDs or IIDs with this method. UIDs are gone when you destroy the object and IIDs are shifted. Instead visualize in your head which "row" in the 2d array corresponds to which object.