You need to modify Coppermine itself to accomplish this. Open ecard.php and look for the template params here
$params = array('{LANG_DIR}' => $lang_text_dir,
'{TITLE}' => sprintf($lang_ecard_php['ecard_title'], $sender_name),
'{CHARSET}' => $CONFIG['charset'] == 'language file' ? $lang_charset : $CONFIG['charset'],
'{VIEW_ECARD_TGT}' => "{$gallery_url_prefix}displayecard.php?data=$encoded_data",
'{VIEW_ECARD_LNK}' => $lang_ecard_php['view_ecard'],
'{VIEW_ECARD_LNK_PLAINTEXT}' => $lang_ecard_php['view_ecard_plaintext'],
'{PIC_URL}' => $n_picname,
'{URL_PREFIX}' => $gallery_url_prefix,
'{GREETINGS}' => $greetings,
'{MESSAGE}' => bb_decode($msg_content),
'{PLAINTEXT_MESSAGE}' => $message,
'{SENDER_EMAIL}' => $sender_email,
'{SENDER_NAME}' => $sender_name,
'{VIEW_MORE_TGT}' => $CONFIG['ecards_more_pic_target'],
'{VIEW_MORE_LNK}' => $lang_ecard_php['view_more_pics'],
'{PID}' => $pid,
'{PIC_TITLE}' => $pic_title,
'{PIC_CAPTION}' => $pic_caption,
);
Add in the new ones at the end, like so:
$params = array('{LANG_DIR}' => $lang_text_dir,
'{TITLE}' => sprintf($lang_ecard_php['ecard_title'], $sender_name),
'{CHARSET}' => $CONFIG['charset'] == 'language file' ? $lang_charset : $CONFIG['charset'],
'{VIEW_ECARD_TGT}' => "{$gallery_url_prefix}displayecard.php?data=$encoded_data",
'{VIEW_ECARD_LNK}' => $lang_ecard_php['view_ecard'],
'{VIEW_ECARD_LNK_PLAINTEXT}' => $lang_ecard_php['view_ecard_plaintext'],
'{PIC_URL}' => $n_picname,
'{URL_PREFIX}' => $gallery_url_prefix,
'{GREETINGS}' => $greetings,
'{MESSAGE}' => bb_decode($msg_content),
'{PLAINTEXT_MESSAGE}' => $message,
'{SENDER_EMAIL}' => $sender_email,
'{SENDER_NAME}' => $sender_name,
'{VIEW_MORE_TGT}' => $CONFIG['ecards_more_pic_target'],
'{VIEW_MORE_LNK}' => $lang_ecard_php['view_more_pics'],
'{PID}' => $pid,
'{PIC_TITLE}' => $pic_title,
'{PIC_CAPTION}' => $pic_caption,
'{RECIPIENT_NAME}' => $data['rn'],
'{RECIPIENT_MAIL}' => $recipient_email
);