How to change the Login page URL from to a custom one.

This is related to my query at “How to read Base Url in a Portlet - webMethods - Software AG Tech Community & Forums

Now client wants this page to be my start page . However when I make it my start page The URL remains “” and not “/onboardBD” which was my custom alias. I use this alias to detect where the click came from and display appropriate content.

Please help