Eval() in AS3?!

[AS]
xml_data = new XML(event.target.data);
data_result = (xml_data.server.connection).toString();
[/AS]

This codesnippet returns data from an XML document but I need to make the part server.connection dynamic, as a variable string. Instead it could be xml_data.server.serverURL. I´ve looked at examples on net and here on Kirupa but still - Nope. :-/