[E2010] [TA] [C#] [Windows] Modify the email body with Transport Agent

I'm looking for a C# example of a Transport Agent that will modify the body of an email message in Text, HTML and RTF formats.  The Body Conversion sample in the Transport Agent SDK only shows how to modify the Header and Footer of an email not the Body.  I will need to search the email Body for certain keywords and insert test after the found keywords. 

Thanks.