ESB 2.0 : How to cCnfiguring XPath Resolver

Question

I am new to ESB 2.0 with BizTalk Server 2009, Can anybody explain how to configure the XPath Resolver in ESB 2.0. In my case I am receiving a message through OnRamp, based on the content of the message I have to route the message. Details: <Root> <DataValue> </DataValue></Root> Based on DataValue We have to route, DataValue should not be promoted. How do I achieve this using XPath Resolver.

Thanks in advance.