JAX-WS Kerberos authentication from WebSphere

I'm trying to write a small servlet which is a plugin in a WebSphere application on Linux. The servlet will make web services calls to a service hosted on a Windows server that's part of an AD domain & uses Integrated authentication.

I'll be using JAX-WS and would like to use WS-Security with Kerberos Token authentication. The Kerberos authentication is being mandated by the Windows service because it relies on Windows Auth - something I can't change.

The authentication will be for a single service account in the AD domain - an account dedicated to the servlet which is permissioned within the AD domain.

Does anyone have some pointers on this? I've read the sg247771 (Implementing Kerberos on WAS), but can't locate a scenario which matches the above - same for the WAS docs online. I suspect I'm just missing something obvious. Alternatively any other docs that would explain the configuration I'm after would be great. It's entirely possible that my googling skills have failed and I'm using completely the wrong keywords.....!