The USB specification provides a mechanism, called “vendor requests,” to create your own custom USB commands. This project shows how to implement these requests. Application note AN45471 contains detailed information. Using this project with the USB Control Center, you can do things like sending packets from the PC to the FX2LP board to update the onboard LEDs and 7-segment readout.
Note: To modify and rebuild the project, you need Keil μVision2 IDE that is also provided with the FX2LP DVK. The DVK setup can be downloaded from here.