oracle rman full database recover

I want to restore a full database backup of a databae in noarchivelog, but not the last backup. How can i select the full backup to restore?

From serverfault Guille

• If you have a proper backup, you can specify the point in time of the restore as follows:

   RUN
   { 
       SET UNTIL SCN 1000;    
       # Alternatives:
       # SET UNTIL TIME 'Nov 15 2004 09:00:00';
       # SET UNTIL SEQUENCE 9923;  
       RESTORE DATABASE;
       RECOVER DATABASE;
    }
  

  Look into Oracle documentation at http://tahiti.oracle.com for your specific Oracle version for more details.

  IC.

  Gaius : In NOARCHIVELOG mode you can't do a point in time recovery - where are the archive logs to get you there?
  From $pageUsers[$post.author].name