I’m no expert at ”the Internets”…
Neither do I really understand what you are trying to say…
But, however, let us give it a try...
If you want “MS Word” (because that’s the program that is loaded and handles the data) to do what you want I would guess that you would have to look for some form of API-language that lets “MS Word” communicate with the target file on your server. You should be ably to find information about this, if there is any, at MS web site.
Another way of handling this is to create a CMS and let the user, through a web application edit the word file. If I’m not mistaken, Word now supports XML, which should mean that you would only need a “simple” CMS that can handle XML, and the format tags that “MS Word” XML files use.
... Once again, I’m no expert. Good luck.