How to generate translation file for a custom Drupal 7 module?

I'm using CentOS 5.5 Linux (without X), PHP 5.3 and Drupal 7.0.

The core language of my site is Russian (not English)!

I've created a game.info and the following game.module which generates 3 blocks for the front page:

function game_block_info() {
  return array(
  'game_main' => array(
    'info' => t('Set FlashVars and show the flash game.'),
    'cache' => DRUPAL_NO_CACHE,
  ),
  'game_winner' => array(
    'info' => t('Show the winner of the last week.'),
    'cache' => DRUPAL_NO_CACHE,
  ),
  'game_leader' => array(
    'info' => t('Show the leader of the current week.'),
    'cache' => DRUPAL_NO_CACHE,
  );
}


function game_block_view($block_name = '') {
  global $user;

  if ($block_name == 'game_main') {
    if (user_is_logged_in()) {
      $content = t('User is logged in.');
    } else {
      $content = t('User is an anonymous user.');
    }
    drupal_set_message("<pre>$output</pre>\n");
    return array(
      'subject' => t('Main Game'),
      'content' => $content,
    );
  } else if ($block_name == 'game_winner') {
    ....
  } else if ($block_name == 'game_leader') {
    ....
  }
}

It works ok, but I need all strings to be in Russian and do not want to hardcode them into my game.module file.

Do I need to create the 3rd file called game.po and add it to the game.info?

How can I create a .po file? I would prefer a simple editing of that file if possible, without obscure tools.

I've also tried a tool:

# xgettext -n game/game.module --keyword=t
xgettext: warning: file `game/game.module' extension `module' is unknown; will try C
game/game.module:87: warning: unterminated character constant
game/game.module:100: warning: unterminated character constant