Have a script that injects values into the HOSTS file?
It's a bit of a sledgehammer approach (and needs to be done with GREAT CARE - as if you need to rename your Core / change its IP, that can go bite you in the behind).
As a potential, you may use it as an alias - i.e. "My ProxyCore" instead of "MyActualCore" -- and if you have any method of identifying which devices are likely to use this methodology (i.e. "all laptopts" / "all devices that are at site X -- can be identified via default Gateway" (for instance) ), then you can get THOSE guys to use the "MyProxyCore" HOSTS- based entry to move along.
It's not a super-clean solution, but the lack of DNS is a big issue (granted, even where DNS exists, there's usually some problems with it).
That's essentially the trick we ended up pulling at a customer of mine in the past where we've had to deal with markedly unreliable DNS ... so essentially we just created our own DNS alias that would also work "on corporate network" ... and by using the DNS alias, we could always switch / change the Core on the coporate network & then just needed to update the DNS-alias to reflect the new reality.
Does that make sense?
Yes it makes sense, I'm just not terribly great at scripting. I'll be researching the possibilities of just setting up a DNS at our clients site, it seems like it will be the best solution even if it means more effort. Thanks for the help!