Sending data to and from a Macromedia Flash movie to any hosting application will require a call to the FSCommand function, and this is done inside Macromedia Flash during design of the clip. So you donot have any straight forward method to capture data, because you do not host it, and you do not have FSCommand functionality built on flash movie.
The requirement of you is type of hacking. You need to capture data from low level. WinPCap, or SharpPCap will be of some help.