i think you need to use a program external to php. for example word2x if you are running *NIX. you are better off just converting your documents to html anyway, but supposing you want to display word documents that get updated you could just have something like this:
//php code
exec("word2x -f html /path/to/word.doc /path/to/word.html");
include("/path/to/word.html");
//end php
im afraid that the word2x for html is not fantastic, but it is a work around. You wont get the document displayed exactly as it was in word. it needs some fiddling. You can of course alter this script to do it dynamically, but be careful whenever you use exec.
you also need to make sure that the webserver has write permissions wherever you decide to create the word documents as html, and read permissions for wherever you choose to store the word files.