Add column

Hello I want to add a new column with a randon number, I have used this code, but now is possible add a new column in Flamingo?

Maybe:

function flamingo_columns( $columns ) {
    $columns['sequencenumber']="Numero";
    return $columns;
}
add_filter( 'manage_flamingo_inbound_posts_columns', 'flamingo_columns' );

add_action('manage_flamingo_inbound_posts_custom_column', 'print_flamingo_mobile', 10, 2);
function print_flamingo_mobile($column_name,$post_id) {
  if ($column_name=='sequencenumber') {
    echo get_post_meta( $post_id, '[rand-generator]', true );
  }
}

RANDON GENERATOR CODE

// A?adir número random a formulario contact form 7 
// SHORTCODE: [rand-generator]

function wpcf7_generate_rand_number( $wpcf7_data ) {
    $properties = $wpcf7_data->get_properties();
	$shortcode = '[rand-generator]';
    $mail = $properties['mail']['body'];
    $mail_2 = $properties['mail_2']['body'];

    $subject = $properties['mail']['subject'];
    $subject2 = $properties['mail_2']['subject'];

    if( preg_match( "/{$shortcode}/", $mail ) || preg_match( "/[{$shortcode}]/", $mail_2 ) ) {
        $option = 'wpcf7sg_' . $wpcf7_data->id();
        $sequence_number = (int)get_option( $option ) + 1;
        update_option( $option, $sequence_number );
        $properties['mail']['body'] = str_replace( $shortcode, $sequence_number, $mail );
        $properties['mail_2']['body'] = str_replace( $shortcode, $sequence_number, $mail_2 );
        $properties['mail']['subject'] = str_replace( $shortcode, $sequence_number, $subject );
        $properties['mail_2']['subject'] = str_replace( $shortcode, $sequence_number, $subject2 );

        $wpcf7_data->set_properties( $properties );
    }
}
add_action( 'wpcf7_before_send_mail', 'wpcf7_generate_rand_number' );