parenting spawned objects

I need to know how an object that was “added” in the game engine during a game -or simply not parented before- can be immediately parented to another object or empty. An example would be someone picking up an item and then carrying it in their hand. Or someone switching between displayed items using an inventory.

I don’t think that this can be done without a script but I may be wrong. And if
I am not, if anyone has said script it would be really awsome if they could help me out.