[xml] libxml2 question: how can I insert the <? xml-stylesheet ... ?> tag in a document

["LE BRETON Philippe" <philippe lebreton c-s fr>]

Hello,

I'd like to know how I could insert the special tag <? xml-stylesheet
... ?> in a document, just after the <?xml version="1.0" ... ?> and
before the Doc root element ??
I currently use libxml2 version 2.5.10

Best regards