I assume you're using a DHA-S690, if so there is no device that can control this from the stock head unit, with the exception of using the Alpine Vehicle Hub and a BMW/Alpine interface.

As the DHA-S690 only has AI-Net or stand alone control options, none of the Alpine/BMW adapters for CD Changers will work as they all use M-Bus mode. The Intravee is the only AI-Net mode adapter, but the DHA-S690 is not yet supported.