Croatia to Zurich

Suggest you explore long distance bus lines like Flixbus, DB Bus (run by the German Deutsche Bahn train company) and the Arriva Croatian bus company (taken over by Germans, was called Autotrans). Main cities are now linked by comfortable buses similar to ones used by tour groups. My last DB Bus from Zagreb to Munich had wifi and snacks service. Some Croatian tour bus companies may do part of that route, but they do not tend to be punctual or well-financed. Also, consider a loop from Zurich or Zagreb - but the cost of Zurich will be much higher. Search online for long-distance express bus routes, they change all the time. Also the website Bahn.de will tell you if it is cheaper by train. There are Europaspezial prices for tourists entering the EU countries from Zagreb, for example. Also regional train passes on the slower regional trains can be remarkably cheap.

If you're asking about Rick Steves Tours, then no, we don't have any that connect Croatia and Italy.