Tests if the argument is a reference to a cell or range of cells.
Returns TRUE if value is a reference to a cell or range of cells and FALSE otherwise.
returns TRUE, because C5 refers to a cell.
returns TRUE, because A1:B3 refers to a range of cells.
returns FALSE, because "A5" is text, not a cell reference.
returns FALSE, because NA() is an error, not a cell reference.
returns FALSE, because cell A9999999 does not exist.
where range1 is the named range A1:B3, returns TRUE.
where range2 is not defined, returns the #NAME? error
where cell C1 contains the text "D1", returns TRUE, because INDIRECT returns a reference.