Edit in JSFiddle

<!DOCTYPE html><!-- PÉLDA KREATÍV -->
<html>
<head></head>
<body>
<script>
var parsed = (document.location.href.split('#')[1]||'').split('&');
var params = parsed.reduce(function (params, param) {
	var param = param.split('=');
	params[param[0]] = decodeURIComponent(param.slice(1).join('='));
	return params; 
  }, {});
</script>
  <a id='creativelink' target='_blank'>
    <img src='...'>
  </a>
<script>
var creativeLink = document.getElementById('creativelink');
creativeLink.href = params.clickTag;
</script>
</body>
</html>