Restrict computer access

We have an active directory domain with multiple OU’s set up. We have an outside vendor who needs to access 5 computers on our network via remote desktop. I want to set them up with a domain username and password that only allows them to access these 5 computers and nothing else.

Not really sure how to go about this and I will admit this is not really my “normal” area of expertise, but I’ve been asked to get this setup.

Any help would be greatly appreciated.