well given the way coppermine was imported into photopost but your integrating with
vb maybe your userid's dont match but the issue here is there is not really a script for this.
The script I posted here is one I use for people who import phpbb to vb3 and then you need to rewrite userid's
However if your coppermine id and names are different than the forum the only suggestion I would have at this point is to use phpmyadmin and do a sql query to update the userid say =1 where its 8 in photos and comments etc
UPDATE photos SET userid='1' WHERE userid='8'
Its not an easy task for sure