I am not quite sure if your question is

• how you should structure the XML file,

• how you can build the XML for printing to a file,

• or how to read an existing XML file.

For building and XML file, XML::LibXML and XML::Twig are very convenient. For reading an XML file, consider XML::Twig or XML::Simple (all available from CPAN). You can also use XML::DOM, but I find the above modules easier to handle.

If none of the above helps you, please rephrase your question.

pike