RAT()

    RAT() returns a number showing the starting position of the last
    instance of a specified substring within another character string.

Syntax

    RAT(<exp C>,<exp C>)

Returns

    An integer numeric value.

    If the substring is contained within the target expression, RAT()
    returns the starting character position of the substring.  If the
    substring is not found, RAT() returns zero.

Usage

    RAT() is similar to the AT() function except that scanning begins from
    the right, therefore locating the last instance of a substring within a
    specified string.