In addition to what JAXBA wrote, try using Matrix to price the specific flights you want. (E.g., from FRA to BKK, and in the routing codes field, enter the specific route you want, such as

AY1412 AY101 AY5115

on the outbound, and

CX700 CX 280

on the inbound. For the codeshare, can add a comma and the CX flight number.

That should let you know how it prices before you call the airlines.