get button to move camera like key press

I have a camera set to go from one postition to another using the keyboard as follows-

Vector3 positionA = new Vector3 (-45, 15, 0);

		Vector3 positionB = new Vector3 (20,8,-1);
		Vector3 positionC = new Vector3 (28f,9f,-5f);
		Vector3 positionD = new Vector3 (40f, 7f, -13f);
		Vector3 positionE = new Vector3 (-23,14,-81);

		Vector3 positionF = new Vector3 (-.25f,3.5f,-2.25f);


	if (Input.GetKey (KeyCode.E))
			newPosition = positionA; 
		if (Input.GetKey (KeyCode.E))

	 if (Input.GetKey (KeyCode.R))
			newPosition = positionB;
	 	if (Input.GetKey (KeyCode.R))

and so on… I want to have a GUI button click move it to the same coordinates and I am getting a little stumped as to calling those new positions

any help would be greatly appreciated, thanks!

Old GUI:

New GUI: