Zurich to Milan, visiting alps

We are arriving to zurich airport. We will have only 1 day to spend in zurich, then head over to italy but want to see the swiss alps before going to italy. Could someone suggest us a plan that would cover a train ride from zurich to swiss alps and then to italy. If it is worth breaking the journey at swiss alps we are open to that as well. Appreciate any help in this regard and the best train passes to get for our journey. We are travelling to Milan, Venice, Florence and Rome in Italy by train.

If the day is nice you can take a train from Zurich to Luzern then the WILLIAM TELL EXPRESS. The William Tell is a boat trip from Luzern down to the other end of the lake at Fluelen connecting with a panoramic train over the alps to Bellinzona. At Bellinzona there will be a connecting train to Milan. The WILLIAM TELL boat leaves in front of the Luzern station at 10:12 am so you would want to get a connecting train leaving Zurich at 9:04 am arriving in Luzern at 9:49am.
If the day is raining you could take the train dircet from Zurich to Milan through the alps.
Dick