Returns a value or the reference to a value from within a table or range. There are two forms of the INDEX() function: array and reference. The array form always returns a value or an array of values; the reference form always returns a reference.
INDEX(array,row_num,column_num) returns the value of a specified cell or array of cells within array.
INDEX(reference,row_num,column_num,area_num) returns a reference to specified cells within reference.