Generating a Word document based on a Web Form

I'm writing an application for generating a document out of user pre-filled form. i.e.:

1. the user fills in a form including some checkbox, radio buttons etc..
2. the relevant text is pulled out from the DB
3. The data should be written into a word document - including some dependencies (auto开发者_如何学JAVAmatic numbering,and other designs)
4. The user may preview or download the file

My Question's:

1. which modules should be used in either PHP or ASP.NET code for establishing A Word document? Shell I use HTML/COM/OpenOffice XML?
2. How should the "preview" function be implemented?