If you mean nsxml.so module (either from AOLserver CVS or ArsDigita downloads) I have a preliminary doc that covers the basics and has small example. E-mail me if that's what you're after.
If I'm reading your question correctly, you need to use:
ns_xml node name $node_id
ns_xml node type $node_id
name is the node name, type is the node type (e.g., "attribute" etc.)