hyperlink in word documnet by using interop dll

Question

Hello every one

i go the output  insert hyperlink in word document by using interop dll 

code

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 object address = @"http://www.google.com";  

 object screentip = "Welcome to google";

 object text="Google";

 object missing = System.Reflection.Missing.Value;

 object start = 0, end = 0;

 Word1.Range rng = oWordDoc.Range(ref start, ref end);

 oWord.Selection.Range.Hyperlinks.Add(rng, ref address, ref missing, ref screentip, ref text, ref missing);

this code is working perfectly when i run this code is google when i click google hyperlink googl.com website will be open

but i want code for 

inserting the hyperlink in same word document headings...

this is my urgent requirement

thanks..