Well, you would have to rearrange things in the tpl_header.php file if you want to move the Sales Message below the category tabs in the header.

I don't think you could use a Word file in that place, anyway.

Give us an idea of what exactly this message will say, and exactly where (relative to the category tabs in the header and the breadcrumbs) you want it. My sense is that it would probably be easier and just as effective if you didn't use the tagline, but put your message in the main page body, below the Welcome message.

Also, pasting stuff into Zencart from Word or any WYSIWYG editor isn't the hot setup. Better to add an HTML editor to Zencart and use the editor in define_main_page.php or write the HTML yourself.