You can use Word's automation API to do this, but you'll quickly find that there is almost no documentation for C++/COM anymore. MSDN seems to only have the .NET interop API documented, and if your Google skills are good, you may be able to get the older MSDN pages, but even those would only have VB6 examples. Since you want to avoid .NET I assume your C++ and COM skills are good. If so, you should be able to put together some code based on the VB and .NET documentation out there.
Here's a decent article from 2004 that shows how to access the Word API from VC++ :
Use that article to get started with how you can get going with C++ and COM. Once you get that working take a look at this article:
How to: Search for Text in Documents
That article is for .NET but once you've got COM access, the method/property names would be the same. So you can just convert that to equivalent C++ code, and that should be what it takes to do what you are trying to do.