It sounds like you sort of want to have two blogs a main one and a secondary. With the secondary only accessible from a link on your main page. Why not create a new blog, in a subdirectory, and only link to it from your main blog.
Or, conversly, you could add the RSS feed from the above blog to a page on your main page. Then you would want to hide the secondary blog behind a robots.txt.
Or look at something like
the multiply plugin, which would allow you to run the blogs from the same admin panel. Haven't checked it out but if it uses the same database, then you could use the same template and it wouldn't look like you did anything more than change pages.