FilesMatch

I want to generate links with my code like "index_flotsam.php" and "index_jetsam.php" and have apache ignore everything but "index.php". So if the user clicks on "index_flotsam.php" it will just take them to the file "index.php" but will still display the url "index_flotsam.php". I'm using Apache 2.2.4. I have a feeling I could probably do this with the FilesMatch directive, but I'm not entirely sure how. Any ideas?

Thanks!