The "WSDL: HPD_IncidentInterface_Create_WS" is statically assigned by the python setup script.
I found a second (hidden?) setup page which walks through setting the app up if you have a custom remedy staging form. Basically you have to manually setup your remedy.conf file instead of letting the setup script do it:
Also, in most cases the fields actually required by your Remedy system are only a subset of the required fields in the WSDL file. The Splunk Add-on for BMC Remedy provides a remedy_fields.conf file with preconfigured required fields for both incident creation and update. The required fields in this file override the required fields in the WSDL. You need to customize this file to include all of the required fields for your Remedy system.
For details, see documentation: http://docs.splunk.com/Documentation/AddOns/released/Remedy/Specifyingrequiredfieldsforincidents