We recently purchased a custom domain name through WordPress.com, which is providing hosting for my organization's blog. We were interested in using the domain for other services, and wanted to map these to a subdomain. However, in the Automattic interface there does not appear to be a way to generate a new DNS CNAME. A related issue was reported previously at http://en.forums.wordpress.com/topic/adding-a-dns-cname?replies=4, but the critical bit about setting up the subdomain was not included in the forum.
How can I set up a subdomain in Automattic that points somewhere other than WordPress.com, or is that not possible? Any help would be appreciated.
The blog I need help with is cimarchivists.org.