[Koha] Using bulkmarc in update mode

Hello I need to use the bulkmarcimport tool to update records with new data from a marcxml file, so that for each record in the marcxml file, the biblionumber of the updated record in the database matches the key given in the 001 control field of the imported marcxml record, respectively. I know about the -update option, but how do I set the matching criterion as being the 001 marcxml field against the biblionumber database field? Can you help me please? Thank you in advance Rui -- Sent from: http://koha.1045719.n5.nabble.com/Koha-general-f3047918.html