APplication Authenticate Against an untrusted AD domain.

Question

My application in BoxA, member of AD-A, while logged onto AD-A needs to authenticate itself to an UNTRUSTED AD-B. Is this possible. The application itself is third-party so the source code is not available. The domain controllers can ping each other, establishing trust relationship is not an option. Any AD redirection, or host/lmhost spoofing technique or any hack you can think of that will achieve the desired result?

Thanks