This feature is coming. For now, all you can do is set up a temporary list, then run some custom MySQL commands (in PhpMyAdmin) to manipulate the users.
Example: Temp list is 5, main list is 1
1) move all unconfirmed users from list 1 to empty list 5
UPDATE lm_users SET list = '5', cnf = '1' where cnf = '0' and list = '1';2) Send a manual confirmation email with the "Send Email" feature to list 5. Use the "User's Unique ID" message code to output the user's UID with a manually created confirmation link:
http://site.com/listmail/confirm.php?u=!uid3) Immediately after sending the email, move the users back to list 1.
UPDATE lm_users SET list = '1', cnf = '0' where list = '5';Regards