(APM) I have a need to combine two fields from login page for AD authentication

You could probably do two things:

1. Require the user to enter username.clientid in the logon form, or

2. Request them separately and concatenate in a variable assignment agent. Something like this:

   session.logon.last.username = return { [mcget {session.logon.last.username}].[mcget {session.logon.last.clientid}] }