I think I can do it in a day or two, it will probably be done during the weekend. but I can be available during the week for questions and application support.
The only gray area I see in the description is how complex is the parse of the text, since Notes lack of a regular Expression engine, a complex text parse (with a lot of condition or business logic) may require more time.
Other than that I have been experienced in all the things described, I have already used XMLHTTP Windows API to send Notes data to another Web Application and I already have created programs to handle incoming mail.