This sounds like a great idea.
It also looks like the only way to get to CAI without connecting in Europe is JFK-CAI on egyptair. No F.
I have seen F between Europe on Swiss (ZRH) and LH (FRA, MUC has C only).
Swiss F is nice, ZRH a good (small) airport to connect, good F lounge and many Swiss flights to ZRH. I assume your father has some flexibility about the day. You should be able to find seats using some other Star carrier miles.

Another options should be BA via LHR. I was never too enthusiastic about the BA F offering, but mute since it will be the first F experience for your father. Just make sure to also use BA on the US-LHR flight, otherwise he needs to change terminals in LHR.

In any case: the ticket inside the US should be included in the award. It would also be better to have all flights in one ticket, then he is protected all the way if something goes wrong.