I have a custom button on my application page to open a new document from a document template, like you would do directly on a list. The code is similar to:
<a href="http://Site/test/documents" onClick="createNewDocumentWithProgID
'SharePoint.OpenDocuments', false)">Click to create document</a>
This opens my document template in Word without any problem. The document template is coupled to a content type, so all metadata fields are defined.
But now I do want to set metadata (properties) in the newly created document, preferably before the document gets opened so the data is visibile in the Document Information Panel inside Word. This data has to be set dynamically because it's based on parameters defined in the application page. Is this possible?