You don't absolutely need the xml schema listed in the variable. If you do have it, it'll simplify the creation of you xPath statement since you'll be able to browse down the structure of your xml instead or trying to figure it out.
I think the xPath you'll need to use is something like:
/process_data/myXML/soap:Envelope/soap:Body/temp:GetEmployeeByNetworkIdResponse/temp:GetEmployeeByNetworkIdResult/temp:EmployeeInfo/temp:NetworkId
You'll need to add the two namespaces under the properties of you process for the expression to work.
Right click on your process from the Processes view and select Properties, then Advanced. Under Registered Prefixes for Namespaces make sure to add the following:
soap ->
http://schemas.xmlsoap.org/soap/envelope/temp ->
http://kingpharm.com/AppServices/PersonnelYou can replace temp with any id you want (just make sure to update your xPath expression). All children node of GetEmployeeByNetworkIdResponse inherits that namespace by default.
I hope this helps.
Jasmin