Hook up two monitors using doc and laptop VGA ports

I have a Lenovo X230 ThinkPad with docking station. I have two monitors. There is only one VGA port on the dock but the laptop has one as well. I can not get both to work at the same time. If it is docked, one works. If ii remove it from the dock the other works. I am trying to figure out how to configure both to work at the same time with what I have.