php 正则提取XML 指定内容步骤？求大拿帮忙（史上最难）

$string = <<<XML<br />
<?xml version="1.0" encoding="utf-8"?><br />
<stream><MSGCODE>AAAAAAA</MSGCODE><MSGCN>交易成功！</MSGCN><B2CCERTNO>500415</B2CCERTNO><ORDERDATE>2013-11-21</ORDERDATE><ORDERTIME>09:52:23</ORDERTIME><ORDERNO>DGM20131121000009</ORDERNO><ORDERAMT>6.26</ORDERAMT><CURRID>01</CURRID><PAYAMT>6.26</PAYAMT><PAYNO>BC131121095428004271</PAYNO><ACCNO>6226********6770</ACCNO><ACCTYPE>01</ACCTYPE><PBCSTNAME>测试</PBCSTNAME><ACCHASH>fSSczJM0fims1Xpmrvi2pnBtrr4=</ACCHASH></stream><br />
XML;<br />
<br />
preg_match_all('#<(MSGCODE<br><font color='#FF8000'>------解决方案--------------------</font><br>ORDERNO)>(.+)</\1#s',$string,$m);<br />
print_r($m);