No. Admins aren't supermoderators, they're reddit employees, and the only way you can gain control of a subreddit if you're not an admin is by /r/redditrequest, which has very specific criteria. (Moderator has to have been offline from reddit for N days, so forth.) Even admins can't take control of subreddits arbitrarily. If they did, there are a few that would have been gone years ago.