Cloaking Script on Google Adwords

Hello, I am looking for a cloaking script for adwords. I need to show 1 URL as the display URL and on live ad clicks users should go to another URL ([login to view URL] >> [login to view URL]). If a Google Bot, google employees click they should go to abc.com. Also direct links to this page should go to [login to view URL] We would do this with a redirect page in the middle ([login to view URL] >> middle page >> [login to view URL] OR abc.com. If someone goes directly to this page they should go to abc.com. They ONLY go to [login to view URL] if a live Adwords ad is clicked AND they aren't associated with google. Regards