Get USB serial number in C++/MFC application

I need a sample of C++/MFC with source code to get usb's serial number. It runs on Windows platforms include and above XP. Please provide me a C function, passing in argument drive letter of a USB, for example "G:", and returns the serial number of the usb. Please note it's not volume serial number, which is different when the usb is on different computers. It's the serial number that comes with usb. Serial number or any other unique number or string of the usb are OK. I need exe for testing, and get source code at the end. Thank you.