Sample 1 uses INDEX to search for the first occurrence of a 'word' anywhere in a string. If the string is not found, the result is zero.
Sample 2 uses INDEXC to locate the first occurence of any character specified in the excerpt. If no target is found, the result is zero.**
Sample 3 uses INDEXW to find the target excerpt in a string on a word boundary. If the word is not found, the result is zero.
Sample 2: INDEXC
Sample 3: INDEXW