Configuring OAM HTTP Token Extractor

Has anyone configured an OAM authentication module using the HTTP Token Extractor similar to the process outlined in the Docs?  http://docs.oracle.com/cd/E40329_01/admin.1112/e27239/shared.htm#CIHCCBCC

My goal is to use the CA siteminder authenticated username taken from the HTTP header to perform the OAM authentication.

I followed what little there guidance there was, but the only result it that I'm getting the OAM default authentication screen.  My assumption is that the configuration is incomplete, and I'm not sure what values to provide for the authentcation scheme properties such as challenge method, challenge redirect url, and challenge url.