tab completion for "short name" in .mailrc

[John Velman]

I'm setup for completion of the full address after I type in the "short
name" from .mailrc, but sometimes I've got a short name that I don't use
very often, and it would be nice to have tab completion.  For example,
I've got the "mutt-users" list aliased as muttusers.  (Of course now
that I've switched to gnus, I may never use this again, but for
example...) It would be nice to type mutt<tab> and have the list of
completions shown.

I've googled, and looked in the gnus manual, but can't find this
particular situation.  Can someone point me in the right direction?

Thanks,

John Velman