I recently tackled something similar and this may be your problem.

GameObject.Find('objectName') -- Will only find GameObjects that you have created in your scene or dragged from your prefabs into your scene.

Resources.Load('prefab') -- Will Load a prefab from your resources folder in your prefab section, if this does not exist you simply need to create a new folder named resources and move the prefab in to this folder. After loading the prefab you can then Instantiate the GameObject 'prefab' from which you have loaded.

You can now use GameObject.Find('prefab') now that the GameObject has been loaded.