The create object behavior should have what you need, you create it at the origin point you want, and set it's angle based on the object that is creating it. Similar to how the ghost shooter example works that you mentioned earlier, sorry I would provide a sample CAPX file but I am at work and don't have Construct in front of me.
You would just need to have some logic to change the angle/rotation of the turret based on user input (arrow keys, etc...)