Create new node: predefined node reference value?

lets say you made a module named mytracker
I'll write down some functions for adding the functionality you desire

NOTICE: that this code is from an OLD drafted module of my own, it was a tracker made with cck
therefore, this solution might not be the best solution, but it is a working solution (that module is still in use on an intranet issue tracker)

I cut off some extra code, I hope it works, since I won't check for possibly introduced bugs, just let me know if there was any missing function (also I renamed functions to use "mytracker" module name)

function mytracker_preprocess_node(&$vars) {
  if (isset($vars['type'])) {
    $type = $vars['type'];
    if ($type == 'project' || $type == 'issue') {
      $nid = $vars['nid'];
      switch($type) {
        case 'project':
          $project_nid = $nid;
          $add_issue_text = t('Add Issue');
          break;
        case 'issue':
          $project_nid = $vars['field_project'][0]['nid'];
          $add_issue_text = NULL;
          break;
      }

      if (empty($project_nid)) {
        $add_issue_link = '<span class="orphan orphan-issue">('. t('Orphan issue') .')</span>'; 
      } else {
        $add_issue_link = _mytracker_get_link_add_issue_to_project($project_nid, $add_issue_text);
      }     
      $wiki_link_name = '[#'. $nid .']';
      
      $vars['submitted'] = '<b>'. $wiki_link_name .'</b> '. $add_issue_link .'<br/>'. $vars['submitted'];
    }
  }
}

function _mytracker_get_link_add_issue_to_project($nid, $link_text = NULL) {
  if (!_mytracker_is_project($nid)) return _mytracker_get_link_new_issue();
  $node = node_load($nid);

  $link_title = t('Add Issue to project') .' [#'. $nid .'] '. $node->title;
  if (empty($link_text)) {
    $link_text = $link_title;
  }
  $attributes = array('title' => $link_title);
  
  $query_string_args = array('project' => $nid);
  return l($link_text, 'node/add/issue', array('query' => $query_string_args, 'attributes' => $attributes));
}

function _mytracker_get_link_new_issue() {
  $link_title = t('New Issue');
  $link_text = $link_title;
  $attributes = array('title' => $link_title);
  
  return l($link_text, 'node/add/issue', array('attributes' => $attributes));
}

function _mytracker_is_project($nid) {
  $node = node_load($nid);
  return ($node->type == 'project');
}