I would like to know how we can customize the standard login page of SAP enterprise portal to have one more parameter along with the Login ID. In the current portal (non SAP) they have Retailer ID along with Login ID for logging into their portal. Internally the User ID is stored as Retailer ID + Login ID.
For example, lets say Retailer ID is 111222 and User ID is Veena.
The actual User ID becomes "111222Veena" and this concatenated string is stored in the database as User ID. If we need to change the login page to just have user id, the impact is huge as there are many external systems which store the User ID in the same fashion and we also need to provide SSO to these systems.
I would also like to know the impact on the standard authentication mechanism (whether we can use the standard mechanism of logging in) and how much of customization will be involved.
Thanks & Regards,