Find Replace into Template PlugIn Code

[SorentoUltimate]

i try that code:

PHP Code:

      $find_string  = fetch_template('greeklish2greek_SHOWTHREAD_fnd');
      $repl_string  = fetch_template('greeklish2greek_SHOWTHREAD_rpl');
      $vbulletin->templatecache['SHOWTHREAD'] = str_replace($find_string, $repl_string, $vbulletin->templatecache['SHOWTHREAD']); 


but not work, with error:

Warning: fetch_template() calls should be replaced by the vB_Template class. Template name: greeklish2greek_SHOWTHREAD_fnd in [path]/includes/functions.php on line 4097

Warning: fetch_template() calls should be replaced by the vB_Template class. Template name: greeklish2greek_SHOWTHREAD_rpl in [path]/includes/functions.php on line 4097