>How can I send and recieve data to a COM port over a network(with VFP,ASP,...)?

We are using a hardware product called a RocketPort Serial Hub. You hook the device to your network (not inside your computer) and install the driver software. You write your software as if the serial port was on the local machine and the data goes over the network to the Serial Hub and then to the serial device. Data goes back the same way. They have several products. Here is the vendor's web site

http://www.comtrol.com

(Disclaimer: We just use the product. We don't have any vested interest in the company.)