Group match for high-rated player

I started a little group a few months ago, and one of our members is very high-rated (2420+).  He is interested in playing (for our group) a one-on-one-match with someone from another group, and with a roughly equivalent rating.  Three open challenges I posted were accepted by other groups, but in each case, no one signed up for the match. 

Does anyone know of any particular Chess.com groups that have a significant number of high-rated players in that rating range, where it might be possible to get a match opponent for him?

Thanks!

About a  year ago I was invited to join a group that only took members with ratings over 2100.  I belong to enough groups already, so declined the invitation.  And right now I cannot think of the name of the group.  If there is some way to search for groups based on ratings of players, you may be able to find that group.

Thanks, bishopson.  I don't believe there is a way to search for a group on that basis.  But it's good to know that at least one group exists like that.  :)

Unless he doesn't care if his opponent is...er, assisted, he should be very careful about the challenges he accepts at that rating level.

That's a good point.  I do know he is actively playing on Chess.com, but perhaps open group challenges are not the right way for him to obtain an opponent.  Thanks.  :)

One other option is he could challenge one of the titled players.  With his rating that high, it's likely one of them will take him up on the challenge.

Well, he is actively playing, but we want him to play for our small group in a team match (except he would be the only team member).  But along the lines of what you suggest, I was thinking he could message a high-rated player that he has played before and see if that player is willing to play him in a team match as opposed to an individual match.