I See several possibilities depending on how much room you have behind your boat and how far it is to be out of your docckage area and into open water. If you have enough room behind your boat and you wish to power out(or sail?) with the bow pointed out to the exit, I would take my starboard bow line to the cleat at the end of the dock while pushing or letting the boat drift back with the prevailing wind.This should let the boat stream out from the end of the finger the wind "weather cocking" the boat so that the bow is pointing somewhat in the direction of the exit. Then , with a wheel hard to starboard (or a tiller hard to port) carefully apply power in reverse continuing to back up while slipping of the bow line from the dock cleat(BTW, when you cleat to the dock just slip the bowline around it and then back to the boat so you can let go of the end and let it slip past the cleat and oull it aboard). Then when you feel you have enough room, turn wheel hard to port(tiller hard to starboard) and give a quick burst of power. This should push the bow enough to port that you should now be pointing towrd the exit, or close enough that you can continue to power straigth out. ( Again, you need enough room behind your boat for this.,Otherwise you may have to repeat the wheel hard to starboard, gentle power in reverse and then back to wheel hard to port with a burst of power in forward to get her to face out toward the exit.
If it isn't too far out of your slip to open water you could reverse all the way out toward the exit in reverse. Slipping the port bow line around the cleat at the end of the finger would help this manuever as the wind pushes your bow to starboard and the propwalk brings your steern to port, now facing with stern toward exit and coninue backing out,letting bowline slip offf arounf the cleat at end of dock. Rick