I use sendKey function of Shell to input string to the command prompt window.
But I found that when I input double characters such as "\\" or "tt", sometimes it will turn out to be just one char as "\" or "t", sometimes the actual string.
So I want to try to use a loop to send one char at a time, thus i can insert some waittime.
But I don't know how to return the specified char in a string using the char index.