traveling from nice to switzerland

Use the search engine on http://www.bahn.co.uk

Hello

For all European train time queries, www.bahn.de
Train Rail Provider for Italy www.trentatlia.com

#2 it's trenitalia.com (note spelling). Anyway, Nice is in France, so the OP should refer to the SNCF website instead: [www.voyages-sncf.com].

Either:
Nice airport dp 17.30 - Basel airport ar 18.40, Fare about 70 EUR with 1 piece of checked in luggage
https://www.easyjet.com
Basel airport dp 19.37 - Lauterbrunnen ar 22.22, change at Basel SBB and Interlaken Ost, Fare about 65 EUR
or
Nice airport dp 8.00 or 13.45 - Geneva airport ar 9.00 resp. 15.00, Fare about 70 EUR with 1 piece of checked in luggage
https://www.easyjet.com
Geneva airport dp 9.36 or 15.36 - Lauterbrunnen ar 12.55 resp 18.55 Fare about 75 EUR
or
Nice dp by train 7.53 - Ventimiglia 8.42/9.07 - Cuneo 11.26/12.03 - Torino PN 13.25/13.50 - Novara 15.01/15.19 - Domodossola ar 17.16, Fare 27 EUR
Domodossola dp 17.51 - Brig 18.17/18.49 - Spiez 19.24/19.33 - Interlaken Ost 19.56 - 20.02 - Luterbrunnen ar 20.22, Fare about 55 EUR
Total fare about 82 EUR
or
Nice Ville dp by train 10.59 - Geneva 17.14/18.10 - Bern 19.56/20.04 - Interlaken Ost 20.54/21.02 - Lauterbrunnen ar 21.22, Fare about 150 EUR

http://www.ter-sncf.com/Regions/PACA/fr/Default.aspx
http://www.trenitalia.com/
http://www.sbb.ch/en/home.html