InstallAware

I need to extract various values from a short xml file. Is there any example you can provide for parse string that might help me out?
Here is a brief sample - need to get ProxyServer, ProxyPort ...
appSettings opening tag...
add key="ProxyServer" value="10.10.10.98"
add key="ProxyPort" value="8080"
add key="BypassProxyOnLocal" value="true"
appSettings closing tag

First parse for add key=" and then parse for ".
Then parse for value" and then for ".
And so forth...