Suggestions for Paris to Switzerland in 4 days with one or two hotel stays.

Paris to Interlaken by train. Then Interlaken to Lauterbrunnen by train.
Either stay in one place in the valley at Lauterbrunnen or stay in the mountains in Wengen.
Then train to Zurich the night before to fly non-stop to LAX.

or

Paris to Montreux by train. Stay in Montreux. Fly out of Geneva (that would require a connection to get all the way to LA).

What could I see if I stayed at either of these towns? Would like to take Glacier Express. Have you done this excursion?

Travelling from Wednesday through Saturday will only provide two or three days for sightseeing, once travel times are accounted for. By the time you check out of your Paris hotel, get to the station, take the trip to Switzerland and check into your new hotel, the better part of Wednesday will be gone.

You might consider travel from Paris Gare de Lyon to Lucerne, and spend your time there. On the current schedules, there's a train departing at 10:23, arriving Lucerne at 15:05 (time 4H:42M, 1 change at Basel SBB). While in Lucerne you could take a day trip to Mount Pilatus via boat and Funicular one way and then back by Cable Car and Bus. The views from the mountain are spectacular and there are a couple of nice restaurants at the top.

You could also take a day trip to Lauterbrunnen and the Berner Oberland, although it would mean more travel time. The trip is currently listed at 2H:19M each way, with one change. While there you could travel up to Mürren and take the Schilthornbahn to Piz Gloria revolving restaurant, where the James Bond film On Her Majesty's Secret Service was partially filmed many years ago. It's at about 10,000 feet so has great views of the Alps.

If you decide to give this a try, you can travel directly from Lucerne to Zürich airport in about 1H:09M. There are some direct trains so no changes (with luggage) would be required. Whether that's possible or whether you might have to spend one night in Zürich will depend on what time you book your return flight.

As I recall, when you arrive at Zürich airport rail station, there's an escalator from there up to the airport so not too hard. It's a big airport but well laid out. As you might expect, you'll have to pass through the shopping area on the way to your departure gate.

Thank you Ken. That's a great plan! Do you know anything about the Chocolate Train that gives tastes chocolate and cheese. We possibly could extend more days. It seems like there's so much to see in Switzerland.