SSO with different backend user ID's

Hi All,

I am trying to setup SSO between Portal, HR and FI systems. The problem is with the user id's as below.

Portal: LDAP user id

HR: personnel number as user id

FI: FI user id.

Currently there is sso setup between portal and the HR system using LDAP attribute mapping as in Using an LDAP Directory Attribute as the ABAP User ID - Authentication on the Portal - SAP Library

Now I am trying to setup SSO between portal and the FI system as well. Can you please let me know if we can maintain an additional attribute for the FI user name in UME XML for portal or is this going to be a bit more difficult than that?

Thanks for your inputs,

Anand