I would just add that nooru identified in another post that he is used to InDesign.
nooru, you need to recognize that ID is a very different application from Word. Word is a fancy word-processor, and although it has many strengths and automation features, it is be no means an graphics-suite-integrated page-layout application with the enormous power of ID. There are indeed many scripts that have been written, and can be written, for Word, many of them available commercially from third-party developers. In my experience, however, the kind of scripts available for styling in InDesign, such as nested style scripts and their offshoots, are not part of Word's overall development. The applications are designed to do different things.
I leave the expertise on such matters to people such as Macropod, whose knowledge of Word is deep and authoritative. I wrote this post in hopes that you can avoid losing time attempting to do something with the wrong tool. I have seen automated tabletop sewing machines that can embroider intricate patterns. Trying to do the same with a machine not designed for this is, at the posters have noted, very difficult.

Cordially,
Ulodesk