Suggestion to get 100% AC status miles:
YYZ - HKG (AC)
HKG - BKK (TG)
BKK - KTM (TG319 or 335 - direct, non-stop)
Another option would be SQ (SilkAir actually) which flies SIN - KTM direct. A possible routing here is:
YYZ - EWR
EWR - SIN
SIN - KTM
Whatever routing you take, please post a trip report! This sounds like it could be an interesting trip.