No sure exactly what you are trying to do but I have a requirement to display a "Monitoring Consent" statement before a user is display the login form.
I accomplished this by modifying the index.html page. The user is displayed a consent message and two buttons, "Accept" and "Decline". The decline button redirect them to the organization's site home page. The accept button creates a set of cookies to holding the accepted datetime and redirects the user to /niku/nu#action:homeActionId which display's the login page.
V/r,
Gene