I need to find automatically which COM port (COM1,COM2...COMx) has been assigned to a usb device (in this instance it is FTDI serial-usb adapter)

I can list usb devices and get theirs information using DeviceIoControl. To do this, i use some of the code you can found here: www.intel.com/intelpress/usb/examples/DUSBVC.PDF

I get those info:
wVendorID 0403
wProductID 6001
wDeviceID 0600
iSerialNumber A700dAut

But even if i can associate them to a HANDLE (usb device handle), i have no idea about to get the serial port HANDLE that i can use for serial communication, or at least the COM name (like "COM5")

Any idea? Thank you all