Example of how to shove link into Moodle breadcrumbs via HTML/JavaScript...can be used with an 'invisible' HTML block

example.js

<script type="text/javascript">// <![CDATA[
var breadcrumb = document.getElementsByClassName('breadcrumb');
var li = document.createElement('li');
var a = document.createElement('a');
var linkText = document.createTextNode("my title text");
var sep = document.createElement('span');
var septext = document.createTextNode("/");

sep.appendChild(septext);
sep.className = "divider";

a.appendChild(linkText);
a.title = "Test Portfolio";
a.href = "http://example.com";

li.appendChild(a);
li.appendChild(sep);

breadcrumb[0].insertBefore(li,breadcrumb[0].childNodes[0]);
// ]]></script>