I can't remember do they supply the bluetooth pass code (or whatever) on the mouse or somewhere in the packaging?

This could be a problem. The mouse dosen't use a passcode, but can only be paired when the button on the bottom has been pressed. One key thing I forgot. The stack you use must support the Bluetooth HID function for this to work at all. I keep forgetting the multiple stacks on the Windows side, as on the Mac one all the adaptors out share one OS based stack.