How do I extract part of a string?

[chmstry]

Let's say I have the string: "a, b, c, d, e, hi"

I saved it as a .txt file and then converted it to a .csv file. How would I write a code that will extract "d" and/or "hi" from this string?

This is the what I've come up with so far:

//let variable "inLine" contain the input line 

string fourthLetter, sixthWord; 
istringstream inStream; 

inStream.str(inLine); 
getline(inStream, fourthLetter, ','); 
getline(inStream, sixthWord, ','); 

I don't know if this is right. How do I specify which part of the string I want to extract?