[sql]
insert into dups select * from scores where substring(player from 1 for 3) in (select substring(player from 1 for 3) from scores group by substring(player from 1 for 3) having count(*) > 1);
[/sql]
Please, do not hesitate to ask for clarifications if so is needed.
I would be glad to hear back from you whether the above worked or not.

Best Regards,

Dimitar