title: magento how add dynamic url path in system.xml
body: <p>I am working on payment gateway. but i have problem i did google research but couldn't find any solution i hope i'll get solution here so i am posting here</p>
  
  <p>following my system.xml code block</p>
  
  <pre><code>&lt;title translate="label"&gt;
      &lt;label&gt;Title&lt;/label&gt;
      &lt;comment&gt;&lt;![CDATA[&lt;img src="/media/billmate/images/billmate_bank_s.png" /&gt;]]&gt;&lt;/comment&gt;
      &lt;frontend_type&gt;text&lt;/frontend_type&gt;
      &lt;sort_order&gt;3&lt;/sort_order&gt;
      &lt;show_in_default&gt;1&lt;/show_in_default&gt;
      &lt;show_in_website&gt;1&lt;/show_in_website&gt;
      &lt;show_in_store&gt;1&lt;/show_in_store&gt;
  &lt;/title&gt;
  </code></pre>
  
  <p>in this block problem is in comment tag right now here i put static link <code>/media/billmate/images/billmate_bank_s.png</code> please anybody suggess me how to make it dynamic </p>