Best way to get from Zermatt to Como

Where in Lago de Como (Lake Como) re you trying to get to?

If you mean the town of Como, train to Visp or Brig, then a train to Domodossola, there take the Cento Vallee train to Locarno then a train to Como. This way is a little longer timewise vs going to Milan and back tracking, but should be less expensive and a lot more scenic.

Headed to The Sheraton Hotel

If you mean the Sheraton Lake Como Hotel in Cernobbio, you could go only as far as Chiasso, Switzerland and take a taxi from there. Chiasso is the last stop on the rail line going south from Lugano in Switzerland and is about equidistant from Como San Giovanni station.

If you traveling on a Swiss Travel Pass, or Half Fare Card, even though the route cuts through Italy, it is fully covered if you use the Cento Vallee Express from Domodossola.

By car, if you have one. The drive, especially on the swiss side, is spectacular. The quickest is to go over to Andermatt, and then take the St. Gotthard which dumps you into Italy. You exit Lugano.

Alternatively, you can take the Simplon Pass, through Domodossola, and then cut across to Locarno on the SS339. This road is very twisty and goes through an impressive gorge. Go slowly and stay in your lane to avoid the Italian drivers who like to take their corners halfway over the median. Really, it's fine.

Having a car in Zermatt is easy. Their transfer system from the Tasch car park into the town center is super-efficient... a 9-minute affair. Most hotels will pick you up at the station. Be sure to allocate a halfday to do the Edelweissweg, a really fun hike with a beer and sausage stop at the end smack in front of the big-M. It's all beautiful country.