Everything that happens in our dreams is a projection of our thoughts in the inner world restored by images and plots from our memory storage, including unconscious one. Any action in a dream is a thought of the dreamer him(her)self. If to express our desires in physical world we are first of all to use our material body sending impulses from the brain to nerve terminals, in a dream we just need to think of something or somebody.
We don’t control most of our dreams just because we got used to the law of physical world and from force of habit we act with regard of our usual life in awaken state. If you learn how to think differently, accepting that in other dimensions the laws are different, you can multiply your abilities and opportunities. Other world has other laws. Other dimension opens other opportunities.