The door lock is probably programmable via the usb, ie you can add and delete 'keys' with it.
Unfortunately you'll probably need the software intended for that door lock, the manufacturer might supply you with it, however they maight be cagey in case your someone trying to do something naughty.
The lock will see the 5v or the númeration sequence from the host, and then time out after a while and go to a secure mode where it locks the door, that explains what your seeing.
Does your pc do the usual 'dee doo' like you get when you plug a usb device in, or does nothing happen, if the former then you might be able to get somewhere.