[flexcoders] retrieve row # from XMLList w/ Namespaces for combo selectedIndex?

[MicC]

comboBox dataProvider named responseRows = XMLList with Namespace so row data 
looks like:

<MEMBER_CAPTION xmlns="urn:schemas-microsoft-com:xml-analysis:rowset" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; 
xmlns:xsd="http://www.w3.org/2001/XMLSchema"; 
xmlns:ddl2="http://schemas.microsoft.com/analysisservices/2003/engine/2"; 
xmlns:ddl2_2="http://schemas.microsoft.com/analysisservices/2003/engine/2/2"; 
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/";>
  Central
</MEMBER_CAPTION>
<MEMBER_CAPTION xmlns="urn:schemas-microsoft-com:xml-analysis:rowset" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; 
xmlns:xsd="http://www.w3.org/2001/XMLSchema"; 
xmlns:ddl2="http://schemas.microsoft.com/analysisservices/2003/engine/2"; 
xmlns:ddl2_2="http://schemas.microsoft.com/analysisservices/2003/engine/2/2"; 
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/";>
  Northwest
</MEMBER_CAPTION> etc.

I need to set the combo to a default preference e.g. "Northwest" by searching 
its dataProvider for that value and then setting selectedIndex. The code

var msRS:Namespace= new Namespace( 
"urn:schemas-microsoft-com:xml-analysis:rowset");
var temp1:Object = responseRows.(msRS::MEMBER_CAPTION == "Northwest")

finds the "Northwest" row but I do not have the row number to use to set 
selectedIndex of combo. As always, TIA,

Mic