If the domain is parked (earlier I could not reach it) you should be able to map your current WordPress.com blog to the subdomain. Here are the instructions: http://en.support.wordpress.com/domains/map-subdomain/
then be able to transfer it into my website (either at WordPress.com or .org.)
Please read that Support doc carefully, especially concerning "Same Rules Apply" as when you map your WordPress.com site to a subdomain of your standalone site you are not transferring it anywhere; it is still hosted by WordPress.com.
If you need the additional functionality of plugins or external themes or restricted code or anything else we do not have access to here on WordPress.com then do not map your WordPress.com site to a subdomain of your site. Simply export your content and import it to a subdomain of your standalone site instead.