Trigger macro when any cell containing formula changes

Question

I have a worksheet with about 50 cells (containing formulas) that changes depending on cells in an external workbook.

I want to trigger a certain macro when ANY of these

Answer 1

Maybe you can start with this code.

Private Sub Worksheet_Change(ByVal Target As Range)
  Dim rIntersect As Range
  Set rIntersect = Intersect(Target, Application.names("NameOfRange").RefersToRange)
  If Not rIntersect Is Nothing Then
    MsgBox "found" '<~ change to your liking
  End If
End Sub