What about putting the content in an instance of the Featured Content widget? If that doesn't give you enough control, there's also the HTML widget - I think you have a lot of free reign with that one. I guess it depends on whether you need things on an Overview page or in an Activity Stream.
We have a similar need to change the publication date of blog posts because we're in the process of migrating our older blogs from our company website over to the community. The problem is we don't want these blogs to appear ahead of the newer blogs that we have been publishing in the community over the past few months. Is there a workaround for this?