Firstly, you are in the wrong forum. You need to ask this question in an office/word related newgroup.
Secondly, a text search in fact does work. Try it using Windows Search, and type in the expression you want to search in the containing text field. Word document has its format and everything encoded. However, the actual text is still there. You can always open a word document using a notepad, and have a good for yourself.
Thirdly, if you really want to, you can always use Word object model. With that, you can use native search functions within the Application object of word.