Playing with a quick dirty script here ....
, connectionstring, xmlpeek xmlpoke. #, script :
<script language="C#" prefix="custom" >
<code>
<![CDATA[
[Function("fix")]
public static string Fix(string input) {
return Regex.Replace(input, @"localhost\\\w+", "localhost");
}
]]>
</code>
</script>
<xmlpeek
file="config01/app.config"
xpath="/configuration/connectionStrings/add[@contains(@connectionString,'localhost\')]/@connectionString"
property="connectionstring">
</xmlpeek>
<xmlpoke
file="config01/app.config"
xpath="/configuration/connectionStrings/add[@contains(@connectionString,'localhost\')]/@connectionString"
value="${custom::fix(connectionstring)}">
</xmlpoke>