Sure, you can either use a rules token (see the Rules tab), or use an iframe HTML element.
For example, set the <announcements> token to use a file, then insert the <announcements> token somewhere in your layout.
You could also insert an <iframe> element, like this:
<iframe src="C:\path\to\my\file.txt"></iframe>
I would suggest googling iframe to get an idea of how you can modify it to suit your tastes.