He can write to admin, explain his situation and admin can confirm him manually, but i think you are not looking for this.
PK

there's a limit on the "life" of the confirmation request. so after it expires, the user can just start again....
and you can configure the expire time....
I also changed the text that displays when the confirmation mail is sent, to check junk boxes, spam filters etc, and that they only have 3 days (my setting) in which to take action on the confirmation mail, or they will have to start over.
Hope that helps.
Ken

I had alternative thought on this that might help - is it possible to get Moodle to dump a carbon-copy of that registration confirm email back to the Site Administrator?

As Site Administrator, I can set up an email inbox that will just filter based on subject line and store these emails safely (with limited access for security purposes, etc) and, if needed, as Site Administrator I can later filter through these Moodle generated emails and re-send the required email...

Is there a setting in Moodle to have all of the Moodle site-generated emails carbon-copied to a specific mailbox to do this?

I want to institute this into a Moodle site, if possible.  It would then be possible for me to re-send the original email which Moodle doesn't store.  It would also give me absolute evidence that the registration confirmation emails are being sent out by the Moodle system, so I can more accurately advise as Site Administrator that the email went at such and such a time etc and might be captured in your junk box...

Cheers

Ken