Change gameObject within a Transfom

Hi guys, sorry if this is hard to explain.

I have the following code

var checkpoint : Transform;
var checkpoint2 : GameObject; 

function Awake () {
	transform.position = checkpoint.position;
	transform.rotation = checkpoint.rotation;
}

checkpoint is a spawn location, within my game. i have to manually add the prefab/empty object as the spawn location (click and drag into the variable box).

I would like to automatically change that variable, with a different prefab/empty object. This would allow a new spawn location, where ever the new/second prefab is located.

Problem is, you cant Mix a gameobject with a transform.
How can i overcome this?

Surely if i can manually add a prefab into the variable, i should be able to change that variable with another prefab, automatically.

Thankyou

Edit: I would like to make “checkpoint2” the new variable within “Checkpoint”

You can get the transform of the gameobject with

transform.position = checkpoint2.transform.position;