USB Communication

Hi Everybody..

I am really very  new  C# Programming.

My application must communicate with a device with a protocol. This device has RS232 and USB ports.

The protocol looks like: <StartByte><Datalength><Data>. I have searched in internet but I really did not get what I will.

How can I communicate with this Device over USB I think SerialPort is necessarry and enough in this situation.  I need just to give the Com name (Com1--ComX).  And I dont need any driver. Am I right

Thanks.