I'm not sure if anyone is still reading this thread, but I have been looking to do the same thing as stated in the original post. I have a 12x24 living room on the first floor, and the exact same size room above it on the second floor. I want to heat the second floor living room with the heat from the wood stove on the first floor. Also, the first floor living room becomes too hot and almost unbearable (90 degrees when the stove is cranking).
I also wish to place some vents in the ceiling (plaster) to the floor above (hardwood). I did find out that IF YOU ARE GOING TO DO THIS, you must use ductwork. Simply put a sheet metal duct connecting the vent in the ceiling to the register in the floor above. The reason for this is if there is ever a fire in the home, this will prevent the fire from spreading through your floors. If you do use ductwork, once fire reaches the ceiling vent it will make its way in and down the joists. Once the fire gets between your ceiling and the floor above it - it will certainly make its way through the house in no time and makes it very difficult for firefighters to extinguish.
They also sell register vent fans to help assist with air flow if need be. I did a google search under "register fan" and many came up. Hope this helps....