Many people would like to Bootload PSoC5 device from a PC. PSoC Creator provides a bootloader tool to do it via USB and I2C. We now have an App Note that provides a complete USB human-interface device (HID) bootloader solution for PSoC 3 and PSoC 5. It describes how to add an USB bootloader to a PSoC 3 or PSoC 5 project. It also discusses how to create your own bootloader GUI using visual C#. The GUI provided uses the HID interface for communication to perform the whole bootload operation.
Take the source code for the GUI and modify it to suit your needs. Suggestions and comments are welcome. You can find the App Note here, http://www.cypress.com/?rID=57561