Just to be clear: you want to open the document on the server, then create something you can display on a web page in HTML from it?
POI does support doc files, but that part of POI is essentially dead - the developers have publicly said that it is not being developed any more. That means if it can't handle the documents you have, you're probably out of luck. An alternative would be the OpenOffice Java API. Some links about both these can be found on the AccessingFileFormats wiki page.