***Find certain word in variable***

Hey, how can I make it so DOS can find a word in a long sentence in a variable.

Example:

Your mother is a _Insert offensive word here_

What I want to do:

Your mother is a *********
==========================

Using it for a pretty popular IM system for my school I batched up ;)


Would love help I'm good at DOS but no professional.

you can use the magic of set

for example:
set string=Your mother is a _word_
set string=%string:_word_=******%

for more string manipulation reference:
http://www.dostips.com/DtTipsStringManipulation.php

Thanks much appreciated btw!