I have a string that has the following format:
string sample = \"A, ABC, 1, ACS,,\"
As you can see, there are 5 occurences of the ,>
You could do something like this:
sample.Split(',').Take(4).Aggregate((s1, s2) => s1 + "," + s2).Substring(1);
This will split your string at the comma and then take only the first four parts ("A", " ABC", " 1", " ACS"), concat them to one string with Aggregate (result: ",A, ABC, 1, ACS") and return everything except the first character. Result: "A, ABC, 1, ACS".