Tilde not being read correctly

I have written a program that takes a CSV file, grabs the data and creates a new CSV file in a different format. In testing I find that one of the names has a tilde over one of the characters. Example:

Jo緌

After the conversion When I open the new CSV file in Notepad I get what I expect:


Jo緌

However, when I open the file in Excel I get:

Jo瓊o

How do I fix this?