OES Script not based on IP Address but original context


I'm slightly struggling with this.

We have users in multiple contexts that move around different sites.
I can write login scripts that are based on their IP Address so if you are on X site you will get X drives maps.
BUT, ideally i want them to be presented with the same drives irrespective of where they are, but not all users in the same Context have the same login script.

So am I going to have to give up on global scripts and just manually add a login script to each user.

So for example context is AA

I want them to go to site B and site C and still get exactly the same drives.

Someone who has a context of XX I want to be able to go to different sites and also get their XX script

But our support company have recommended going forward all users are put in a USERS Context ....
Now some of these users will want the same login script as those at site AA, and some will want their context the same as those at XX how do i differentiate to run the different login script. as they could login at each site so using ip address doesn't really help.