How can I change the re-direct URL on the WebKit for Captive Portals?

Question

Hi,
I have a guest network at the office that is configured with a captive portal for authentication. My MBP detects that it is behind a Captive Portal when the HTTP WISPr request fails and launches the WebKit (ie. the CNA) as designed and displays the login page. When the login is successful, the Captive Portal displays a success and the WebKit then proceeds to re-direct the browser to http://www.apple.com
Of late, Apple's homepage has become graphic rich and more often than not, loading the page without caching (since the webkit does not cache the webpage loaded) loading Apple's homepage on the guest network takes over 30-90 seconds depending on the traffic on the network. The OS does not allow me to use the network till the page on the webkit has successfully loaded and the "Done" button appears on the webkit and this often becomes irritating.
Is there a method to change the redirect URL to something less resource hungry like http://www.google.com or a less graphic rich Apple page (like http://www.apple.com/library/test/success.html)?
I understand that there is a method to disable Captive Portal Handling, ie.
sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.captive.control Active -boolean false
However, I don't want to disable Captive Portal Handling in the OS as I don't believe Apps that require internet access will handle the lack of the internet well.
Any hints would be appreciated.
Cheers!

Answer 1

Hey again,
I did have a look at it and the Settings.plist file isn't very helpful for the issue I have.
The file defines the probes and exceptions. So you have the default probe WISPr URL in there (http://www.apple.com/library/test/success.html) and the exceptions for specific SSIDs, as an example, attwifi is in the exception list and uses an alternate probe WISPr URL (http://attwifi.apple.com/library/test/success.html). The configuration does not have parameters that would be used by the CNA for the redirect to http://www.apple.com after a succesful Captive Portal login.
Give it a shot on your laptop, get to a random public wifi like ATT Wifi/Starbucks/Guest Wifi's at office spaces/Boingo etc. and after the successful login, your CNA Webkit will re-direct to http://www.apple.com and the "Done" button won't appear till the page has completely loaded and stays as "Cancel" till the page is loaded.