Please fix your post it's unreadable.

There are several ways to generate well-formed and valid XML. You can code it manually or use one of the many Perl modules for it. Since you want to from CSV to XML XML::CSV is something to investigate. I'll bet you a have standard message format so using a template and populate that with data is another option. You will probably want to validate your xml message against a schema so I would suggest something based on libxml, e.g. XML::LibXML::Schema. Last but not least, since you probably have to handle IBAN/BIC you can take a look at: Business::IBAN.

HTH