God is an eternal being and whatever is eternal, transcends space and time. The question assumes someone is thinking of the wrong god, because the god of the Bible is not affected by time, space, or matter. If he is affected by time space or matter, then he's not God. The question is like asking: "What does red feel like"? or "What does red taste like?" Red is not a "thing" to be felt or tasted so those questions don't make sense.
Even if humanity could prove that someone or something created God, we would then have to ask: "Who or what created God's creator, and if we found the answer to that, we would then have to ask who or what created the creator of God's creator". Thus we would end up with an infinite regression and no real answer. 
For a more in-depth explanation of this subject please visit: Who Created God?