You can find him here:
http://en.forums.wordpress.com/topic.ph ... &replies=9
He has something for you???
Actually I don't think Blogdesk will allow you to create them.
Staff is working on a WordPress API that I'm trying to get the attention of the blogdesk designer to pay attention to. (Aside, anyone have an account in their forums? I can't get my activated and it's going on three days now) The new API will allow categories to be worked on via a remote system.
Just trying to help, so if you know this info already.... great! If not, now you do :)