Would that be the server, where the website files are stored and where the XAMPP programme files are stored? -- "YES"
Tried that and the request keeps timing out...
If the IP you are trying to reach is a Local IP ON THE HOST NETWORK - then you have identified the issue, its a VPN configuration problem.
in such a case the address browser address might be http://192.168.11.201
for instance. You might try adding :80 to the address.
BUT if you can't ping it and it times out, you have a routing issue.
Its possible that kind of tunneling is not enabled or supported, VPN clients are fairly unique to vendors - you should look to the vendor docs or the vendor support site/helpdesk/forum to see if that is supported in your case.http://en.wikipedia.org/wiki/Virtual_private_network
Is the server exposed though a non-vpn IP? That might be the easiest route.
That's probably all I can offer on this.