Remember that subjective means a feeling that arises entirely within an individual, whereas "objective" means a feeling derived from or oringinating within an external source--such as God or Humanity.
Wait, so let me get this straight. If I subjectively come up with a moral, and write it down, and then you subscribe to it, it(the moral) then becomes objective?
I think you can say it came from an objective source, but the moral itself is not objective, and subject to your own persinal take on it.