Return a portion of text (formerly called "Substring").
text: The text containing the segement you want to extract.
start at: The position of the first character you want to extract in 'text' where 0 is the first character, 1 is the second, and so on.
end before: The position one greater than the last character you want to extract. If left blank or the number is greater than or equal to the length, it will extract all the way to the end. If end before is less than start at, the arguments are swapped.
- segment: The extracted text segement as specified
If 'text' is
0and end before
2and end before left empty -> segment
3and end before