How do you extract parts of a string?,


say i want to extract a a part of string from the 5th letter to the 10th letter from a string, and copy it into another string. how would i do that? :?:

tell application "QuarkXPress"
	tell document 1
		set us to text of paragraphs whose color is "US" as list
		set the text of every item of us to ""
	end tell
end tell