lillymch, "best stop in Viena" for what?
If you want to look up trains from Vienna (Wien in German) to Ostermundigen, just go to either the Swiss Railways site ( www.sbb.ch ), or the Austrian railways site ( www.oebb.at ) and enter "Wien" to "Ostermundigen", and the desired time and date, and it will show the trains.
I have been reading some of your recent posts, they are very vague and ambiguous. It is difficult to work out what you are asking, so it is difficult to answer. Also, you keep misspelling place names, it is Vienna, not Viena, which is also confusing.
The first thing you need to decide in is where you want to go. Get a map of Europe (print one out from the internet), mark the places you want to go to, and how many nights in each place. Then draw lines between them in the order you want to go.
Then we can answer specific questions about how to get from one place to another.