Solved with:

function myplugin_comment_columns( $columns )
{
    return array_merge( $columns, array(
        \'ruolo\' => __( \'Ruolo\' )                
    ) );
}
add_filter( \'manage_edit-comments_columns\', \'myplugin_comment_columns\' );

function myplugin_comment_column( $column, $comment_ID )
{
    switch ( $column ) {        
        case \'ruolo\':
            if(get_comment($comment_ID)->user_id != "0")
            {
                if(get_comment($comment_ID)->user_id != "1")
                {
                $ruolo = "";
                $user_meta=get_userdata(get_comment($comment_ID)->user_id);               
                $ruolo = "Registrato";
                if(in_array(\'vip\', ( array )$user_meta->roles))
                $ruolo = "VIP";
                if(in_array(\'donator\', ( array )$user_meta->roles))
                $ruolo = "Donatore";               
                }
                else
                {$ruolo = "Admin";}
                echo $ruolo;
            }
            else
            echo "-" ;
        break;      
    }
}
add_filter( \'manage_comments_custom_column\', \'myplugin_comment_column\', 10, 2 );