I need to do a search and replace (possibly using a regular expression search) to append ?pb=1 to every link found in a string. For example in the following html I want to make:-

href="http://mynerja.com/about/balcon-de-europa-nerja/"
into
href="http://mynerja.com/about/balcon-de-europa-nerja/?pb=1".

I need to do this dynamically in PHP for all the links in the string.

Thanks for any suggestions and I hope the above makes sense.

Code:
<li class="page_item page-item-1225"><a class="fadeThis" href="http://mynerja.com/about/balcon-de-europa-nerja/"><span>Balcon de Europa, Nerja</span></a></li>
	<li class="page_item page-item-1452"><a class="fadeThis" href="http://mynerja.com/about/beaches-in-nerja/"><span>Beaches in Nerja</span></a></li>
	<li class="page_item page-item-2958"><a class="fadeThis" href="http://mynerja.com/about/charities-in-nerja/"><span>Charities in Nerja CAS, Nerja Donkey Sanctuary, CUDECA</span></a></li>