Actionscript 3.0 :: Using Shape As Object Movement Boundary?

Let's say you have a room, and a little circle representing the player. Let's say also that you decide to draw a shape overlapping the room, set alpha to 0%, and use hitTestPoint() between this shape and the player to create the movement boundary. In short, as long as the player's centerpoint is overlapping the invisible shape, he/she is free to move around.Now, I decided to make things more complicated and add an obstacle to the room - a table in the center. One would think that cutting a rectangle out of the middle of the invisible shape would prevent the player from being able to move there. No dice, the player passes right through the hole in the middle of the invisible shape. The problem, as I see it, is that when the shape is converted to a symbol for use in actionscript, the entire volume of the movie clip is used for collision detection, not just the shape's volume. No matter what options and settings I play with, I can't get the hole in the shape to stay cut-out when I convert the whole thing to a symbol.

Now, I know I could probably add an extra shape to represent the obstacle, and add extra collision detection into my actionscript. However, given that there will be a large number of rooms in the game, and a variable number of obstacles in each room, this is not an elegant solution. The most elegant solution would be to figure out a way to map the playable area in a room with a single movie clip (/graphic).So, I turn to you fine folk. Can anyone tell me how to convert a shape to any kind of symbol, and preserve features like holes within the shape (as in, not have them glazed over as part of the symbol's body