iPlanet Authentication provider authentication using username only

Is it possible to perform authentication through  iPlanet Authentication provider without password, just username which is stored on ODSEE 11g.

The current setup is weblogic11g +  iPlanet Authentication provider + ODSEE 11g. The user provides a username and password. The goal is perform authentication through a 3rd party and use the username (only) for authorization with the same setup "weblogic11g +  iPlanet Authentication provider + ODSEE 11g"