Return a Exist GameObject

Hi! I have a DLL to save and load a GameObject, I use a script in Unity to get this GameObject. In the DLL I do;

 gameObject go;
 public GameObject Load () {
 ...
   return go;
 }

And in Unity I have

 GameObject Player;
 Player = GameObject.FindGameObjectWithTag("Player");
 public void LoadXML()
 {
     Jugador = usedll.Load();
 }

How can I make sure that a new gameObject is not created and that when using the Load function make the Player be edited?