Explicit GUP IP for roaming clients

Greetings!

Would it be possible for someone to "dumb down" the definition for this setting? Im under the impression, from what i have been able to dig up, that I could put in a local subnet that a remote branch office uses (ex. 10.10.x.x where the X's are multiple internal subnets that house clients for just that office) that could then be defined explictly for a certain GUP?

Im in Policies>LiveUpdate>Policy for the RBO>Windows Settings>Server Settings>GUP>Configure Explicit GUP List>Add area, put in the local class b subnet of the Remote Branch Office in question, added the Subnet mask for a class B and then added the GUP that is local to that RBO (but on a different local subnet than the local clients).

Am i on the right track?

Thanks!!

D.J.