ND -
Thanks for the response. Actually I found the answer and it does use SimpleXML. The confusion I had stemmed from my lack of understanding the object. Here's what I have:
$xmlData = simplexml_load_file($fileName);
$errorMsg = $xmlData->{'AdBaseResponse'}->{'non-pub-notes'};
That piece of it generates the data I want into a a variable without the need for an array.
Thanks again for your help.