VS 2008 ITextSharp - Append Static PDF Page To PDF Generating

This is the first time I've worked with itextsharp. I'm maintaining existing code so most of the work was already done for me. I have a question on how to do this enhancement.

My code currently dynamically generates a PDF with n-pages. I want to remove the code that generates the nth page and instead pull in a static PDF document. So in other words I have these variable data that I'm creating cells and tables from, but my last page is non-changing and we want to move from dynamically generating it to just pulling it in from an existing file.

I think this is the relevant code you would want to see:

Code:
// This method builds the PDF
byte[] bytes = (byte[])BuildPdf(startDT, endDT);
//Clear out the response
Response.Clear();
Response.ClearContent();
//clear out the headers
Response.ClearHeaders();
//add the new PDF headers

[Code] ...

BuildPDF() does all the work with the variably-occurring pages and ends with this:

Code:
// Add footer page
CreateFooterPage();
// Close the document to complete it
PDFDocument.Close();
stream.Flush();
stream.Position = 0;

[Code] ....

It is CreateFooterPage() that I want to change to just open an existing pdf, read it into some object and append it to this.PDFDocument. I know I am way oversimplifying it but simply stated, that's it.