So we were finally able to book and everything's all set. We're doing LHR to BKK (stopover) to DPS, returning to LHR, all on Thai. I originally was going the AC route, but their reward booking tool was down and couldn't process any premium reward tickets, so we transferred the points to ANA and were able to book everything through them. Thank you again to everyone for your ideas/help.

Keeping this post on topic with the OnePass board, I have to say that I was not looking forward to the StarAlliance membership (I had been very accustomed to SkyTeam and have been pretty successful with AF and DL reward bookings), but after my experience booking reward tickets via ANA, am very much looking forward to it. ANA had on-line all of the reward availability in a very clear fashion. It was seamless to book another carrier and the amount of availability via creative routings was impressive. Too bad I am pretty much out of points now, but as I build them back up, I am now looking forward to the *A Alliance.