Best train route from Interlaken to Bellagio?
 

The longest day of travel on my upcoming trip is the day we go from Murren to Interlaken to Bellagio... SO many transfers, it appears. The trip from Interlaken to Varenna is about 5 and a half hours, and involves 2 transfers (not counting the transfers from Murren-Interlaken and Varenna-Bellagio.) It also goes to Milan and then back to Varenna, which seems strange, but I guess unavoidable.

Is there a bus or other tranport I should consider?