Send USB ID through Card Reader

I would like to ask a question about RFID USB authentization. I have industrial machine with pc with WinXp/10. There is a possibility to log into the visualisation of the machine control using USB. Principle is: On the pc HDD is a database with users, their passwords and (when created) USB ID (you plug usb in and when you create new user you can assign usb to it – usb stick is then formated and new UID is attached to the name in the database). Then you can plug USB to the machine and you are logged in.

What I would like to do is to connect RFID card reade to machine USB and then use rfid card or button (I will find the button number stored on it and assign it to the user usb UID in database) then when I get close with this button, reader sends string from button to the pc…. So is it possible to send it through reader to pc like UID – resp. is it possible to “upload” this string to the card reader UID? So pc would think there is a usb with UID of the user?

Thanks for your reply in advance.