[kh99]

I don't know what you mean when you say "my config.php contain collation latin2" - I see a way to set the charset in the config.php but not the collation.

Anyway, I don't really know much about charsets and collation, but I had a look at the vb code and the MySQL manual and I think what you have works because the MySQL server translates the results from the database before sending them. If this is correct, then you should be able to change to utf8 by adding $config['Mysqli']['charset'] = 'utf8'; in your config.php.