I got this to work with only one change - the declaration needs to be Public
Public Function Test(ByVal x As Variant) As Variant
Make sure you have this function in a
module - not in Sheet1 or ThisWorkBook.
If you attempt to examine the argument
x
while debugging you do only see e.g. "Error 2007" for 1/0 but you handle that with the
Evaluate(x)