How can I exclude a public ip from the Hybrid filtering service with Web Endpoint installed?

We have a client who is rolling out the Web Endpoint client. They would like a select group of users to work through the client at all locations other than through their own routers at home, where they want no filtering applied.

Is there a way I can exclude specific public IP addresses from passing through the Hybrid filtering service? These routers are under our management so I have access to all of the public ip's however I can't see an obvious location to configure what I am trying to do? I am basically looking for an Unfiltered Source instead of an Unfiltered Destination

I understand the thinking that all clients should always pass through the filtering service at all times but this is a specific request that I am trying hard not to duck!

We are using Web Security Gateway Anywhere V7.8.2 with client 1.4.7.6.1145

Thanks and Regards

Matt