Sorry it took a while XD , I was thinking what the Arduino could do, but you want to run a program on the PC.
It would require a program on the computer that communicates with the Arduino via a serial connection (the virtual serial port of the Arduino board) and with the displays also via a serial connection.
Are you familiar with creating software for a PC ? It is possible with Java, Python, C++ and many more.
The best thing to do is to find an example program that uses the serial port.
Try a few links in the Communication section of the Playground:
http://playground.arduino.cc//Main/InterfacingWithHardware#Communication
For example using a serial port in Delphi, Delphi tutorial: Bi-directional serial comms- dt4q
The Windows PowerShell is able to use the serial port, http://blogs.msdn.com/b/powershell/archive/2006/08/31/writing-and-reading-info-from-serial-ports.aspx