login auditing

I am currently auditing logins and the audit logs are going directly to a syslog server.

We have an application that maintains its own security and logs into Oracle with an application id (app_user).

Oracle is capturing these logins as for app_user. Is there someway I can use sys_context( 'USERENV' , 'OS_USER' ) to have auditing record the OS user login instead of app_user?  

Thanks

Randy  

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