[mariosipad]

@danilodb

I do not have a clue about how to work with custom columns in calibre and/or COPS, but maybe I can point you in a favourable direction.

In config_default.php there are some settings you might need. Copy these settings to your config_local.php. The settings are:

    /*
     * Custom Columns for the index page
     * to add as an array containing the lookup names configured in Calibre
     *
     * For example : array ("genre", "mycolumn");
     *
     * Note that the composite custom columns are not supported
     */
    $config['cops_calibre_custom_column'] = array();

    /*
     * Custom Columns for the list representation
     * to add as an array containing the lookup names configured in Calibre
     *
     * For example : array ("genre", "mycolumn");
     *
     * Note that the composite custom columns are not supported
     */
    $config['cops_calibre_custom_column_list'] = array ();

    /*
     * Custom Columns for the book preview panel
     * to add as an array containing the lookup names configured in Calibre
     *
     * For example : array ("genre", "mycolumn");
     *
     * Note that the composite custom columns are not supported
     */
    $config['cops_calibre_custom_column_preview'] = array ();

I don't know how it works but I hope it helps you.