Thanks for the replies, but there are some difficulties still. (I did RTFM by the way

)
I tried setting the external and was still seeing the local generated page, however I think that is now an Internet Explorer/Squid issue - I will clear the squid cache and see if that helps.
The problem I have with entering the external IP of the web site is that the ISP hosts it as a virtual domain - which shares the IP address between a number of sites.
My current workaround will be to mirror the external site locally, if I don't find a simple solution to this, I will likely change the domain name of the gateway - as it is not accessible from or serving outside.
Klaus