This function, Is Reference, tests whether a value, an expression, or contents of a referenced cell is a reference to another cell.
ISREF(cellreference)
ISREF(value)
ISREF(expression)
Specify a cell reference, a numeric or text value, or an expression for the argument.
Use this function to test the contents of a cell, a numeric or text value directly, or a function or expression.
If the argument is a reference, this function returns TRUE. If the argument is not a reference, this function returns FALSE.
Accepts any data type for an argument. Returns Boolean (TRUE or FALSE) data.
ISREF(B3) gives the result TRUE
ISREF(R1C2) gives the result TRUE
ISREF(12) gives the result FALSE