Das ist recht einfach, genauso wie das Importieren ;)
Dim se As New NotesSession
Dim exporter As NotesDXLExporter
Dim outputStream As NotesStream
Dim col As NotesDocumentCollection
Set col = se.CurrentDatabase.UnprocessedDocuments
filename = "notes.xml"
Set outputStream = se.CreateStream
If Not outputStream.Open(filename$) Then Error 5002,"Datei " & fileName & " konnte nicht geöffnet werden!"
Call outputStream.Truncate
'-- XML erstellen
Set exporter = se.CreateDXLExporter
Call exporter.SetInput(col)
Call exporter.SetOutput(outputStream )
Call exporter.Process
outputStream.Close