Animated curve drawing between any points dynamically

First of all, I like to say that I am a newbie to flash and you guys rock!!!

Here is my question:

I have a world map on which I display some data. I read long and lat coordinates for two countries from an XML file which is updated with different coordinates everytime. I then map the coordinates to X-Y axis using some projection method.
So, I have x-y coordinates for two countries. I wanna draw a curved line between those countries but curveTo method draws the curve in one shot. I want to animate the curve drawing part so it looks like it is being drawn real time.

any help would be appreciated. (this is driving me crazy. I tried drawing part of a circle, but for countries that are far apart from each other, curve gets too high).

Thanks a lot.