Convert Virtual Key Code to USB Key code

Gosh, I don't know.  I use Microsoft Remote Desktop Connection (RDC) to remote my Windows box. The preference panel has a "keyboard" table with which you define the key mapping.  I also use VMware Fusion to run Windows in a virtual machine on the Mac, and again there is a keyboard panel somewhere in the preferences.

Could you explain a little more about your environment.  Is this a cocoa related issue?  Are you writing a VNC client or something?

Yes. I'm working on VNC client. I don't think there is API to convert virtual key code to Scan code or USB. I found lookup table here . I can use that table for conversion.

FYI: The referred table is not 100% correct. 

Ah, that's interesting.  Even if the code from VirtualBox isn't 100% correct, I'm sure it'll take a long way.  Good Luck with your project.