正则替换有关问题

正则替换问题
$compileContent = preg_replace("/(\{cm:)include\s*(.+)(\})/i", "\$this->inc_file('$2')", $compileContent);

现在 $this->inc_file('$2') 被当做字符串替换了

如何用 $this->inc_file('$2') 返回的结果替换呢

------解决方案--------------------
$compileContent = preg_replace("/(\{cm:)include\s*(.+)(\})/ie", "\$this->inc_file('$2')", $compileContent);