Office documents are proprietary (even though later versions are standardized and 3rd-party products work with them, but it's not enough for Web standardization where everything should work for all platforms), so you cannot present them in a Web application directly.
However, you can represent preview as HTML imitation. For some ideas, please see my past answers:
Convert Office-Documents to PDF without interop
Hi how can i display word file in windows application using c#.net
Read a word file without using Interop.word dll...Do not want to install word in IIS..