Hi there - the simplest way to accomplish this might be without modifying your DNS records, but to instead just to set your WordPress.com site to display your latest posts on the homepage.
You could do that by going under Settings > Reading, and selecting "Your latest posts" next to "Front page displays" - as you see in this screenshot:
http://cl.ly/image/2W3s3f362v2Y
Would you like to try that and see if it accomplishes your goal? It's something you could easily reset back to how it was before if you don't like it.
Let me know how it goes!