[development] Any drupal experts? -- Passing CCK reference to another CCK object as an argument

Hi Would anyone know how to pass the reference of one CCK object to another CCK object during object creation as an argument? (cck = content creation kit) Ex: If i have two cck content types A and B with the following fields. A ( aid, some field) B (bid, aid, somefiled) so that every B is related to an A. When creating a new B object, how can I a pass the reference of an existing A object (ie an 'aid') via an argument (through the URL)? [ this should happen without the user having to enter it manuall -- i.e when the user clicks a particular URL a chosen aid shuold be passed ] Tnx in advance Srimal.