There isn’t a “pure html” way to do this – you’d need to use ASP or PHP or something… I would think that the easiest way would be to use a small content management system to do this. Search sourceforge for CMS, or check out cmsmatrix.com for comparisons.
An alternate method would be to use an include in the web page… for example, if the page is PHP, you could do something like:
Here's the news section:
Where the “news.php” file would be uploaded to the server by the editor and would contain the html code for the news.