[Zope] Database login using ZODBCDA

Hi all, I am running the Z ODBC database adapter to connect to ORACLE databases. To using a ODBC data source, you have to type in datasource name, database user and password (it's impossible to use variables at this point). Is there any way to change the database user and password at runtime, so that every user can login with his own database user? Thank you in advance for any kind of help.