Your entire trip, as specified, is 120K United miles in business, but may not price out online. Plan to call in with segment-by-segment details, DXB-NRT will probably be DXB-BKK-NRT. It may also be able to be booked with 90K US miles if US stays *A.

Note: this only works if booked as a roundtrip. Also you may find F availability and not J, which would be 135K. I'd aim to have that available just in case.