A mouse sends a code back to the host either as a TTL level serial stream (old type) or as a USB serial stream on newer types. The mouse doesn't know where it is, only which direction it is moving and whether a button has been pressed. All it does is send back a byte of data per movement of it's motion sensor. As far as I know, the only command you can send to a mouse is to request it's identity and it responds with either a single letter or in the case of a USB mouse, it's manufacturer and ID strings.
Brian