public bool DifferentFirstPage {get; set;}

// Create a document.

using (var document = DocX.Create(@"Test.docx"))

{

   // Add header support to this document.

   document.AddHeaders();



   // The header used for the first page of this document.

   Header first = document.Headers.first;



   // Force the document to use a different header for first page.

   document.DifferentFirstPage = true;



   // Content can be added to the Headers in the same manor that it would be added to the main document.

   Paragraph p = first.InsertParagraph();

   p.Append("This is the first pages header.");



   // Save all changes to this document.

   document.Save();

}// Release this document from memory.