I am not sure there is enough information in your question to answer it satisfactorily.
All of the services we use for our home office on UCS are accessed remotely with authentication through UCS already. There is nothing additional we need to do.
What is it that you are wanting your remote users to access that would be authenticated remotely through UCS?
Presumably anything that can access the server over the internet and has been configured to do so could use it for authentication.
If you are wanting users to access services locally that use UCS authentication then that would usually be accomplished by setting up a VPN of some sort.