You can designate an owner when creating or editing the blog.
As administrator, Control Panel -> Administration -> Blogs -> Select Blog -> Edit -> enter owner username in "owner"
If you want another access point to the Control Panel you can change the SiteUrls.config controlpanel link
<link name="controlpanel" resourceUrl="controlpanel" resourceName="controlpanel" roles="Registered Users" />
Hope that helps,
Dave