WorksheetFunction.IsError (Excel)

Checks the type of value and returns True or False depending on whether the value refers to any error value (#N/A, #VALUE!, #REF!, #DIV/0!, #NUM!, #NAME?, or #NULL!).

The value arguments of the IS functions are not converted. For example, in most other functions where a number is required, the text value 19 is converted to the number 19. However, in the formula ISNUMBER("19"), 19 is not converted from a text value, and the IsNumber function returns False. The IS functions are useful in formulas for testing the outcome of a calculation. When combined with the IF function, they provide a method for locating errors in formulas.

IsError (Arg1)

Arg1: Value - the value that you want tested. Value can be a blank (empty cell), error, logical, text, number, or reference value, or a name referring to any of these, that you want to test.

Dim booIsError As Boolean
booIsError = WorksheetFunction.IsError(Arg1:=)