Locking down a bluetooth Dongle

I have two desktop computers connected via a KVM switch. one is seriously locked down with USB locks to prevent unauthorized devices from attaching. The KVM switch has two USB ports for a keyboard and mouse. We now have a requirement to have a hand scanner that can be used on both computers. Our current plan is to get a wireless keyboard and mouse and then put a bluetooth dongle that will drive the handscanner. this will allow sharing of the keyboard, mouse and hand scanner. our dilemma is this: other devices can connect to the dongle and circumvent the security measures.

Now for the question. Does anyone know of a way to prevent anything other that the aforementioned hand scanner from connecting to the dongle? I have not found a dongle that will limit parings, and our systems guys have not had much success with things like GPOs.