Find position of character in text

In my script i have a public text, and a variable which shows how many characters that text has. It looks like this:
public int charsInText;
public Text textToWrite;
void Start () {

	charsInText = textToWrite.text.Length;


How can find a specific character in the text by number?
Some pseudo coding as example:


so the 4 character is chosen.

since text is a string with indexer, you can just index it directly:


I case of the word “test” it would give you the last “t”. Remember, that indexing starts at 0, the first character