Option Explicit
'1. da modificare con il percorso del tuo pc e il nome del file da controllare
Const filecontr As String = "C:UsersuserDocumentsMagic BriefcaseEXCEL - VBAExcelvba.altervista.orgGiuseppe - confronto fra due file"
Const nomefile As String = "file da controllare.xlsx"

Sub confronto()
    Dim rngA As Range, descrA As Range, colA As Range
    Dim rngB As Range, descrB As Range, colB As Range
    Dim c As Integer, presente As Boolean, r As Integer
    Application.ScreenUpdating = False

    Set rngA = [a1].CurrentRegion
    '2. in questo caso controlla la colonna B; cambia la lettera in base alla tua tabella
    Set colA = Range("b2:b" & rngA.Rows.Count)

    Workbooks.Open Filename:=filecontr & nomefile
    Set rngB = [a1].CurrentRegion
    '3. anche qua cambia la lettera in base alla tua tabella, come sopra
    Set colB = Range("b2:b" & rngB.Rows.Count)

    Windows("file principale.xlsm").Activate
    For Each descrB In colB
        For Each descrA In colA
            If descrB = descrA Then
                presente = True
                Exit For
            End If
        Next
        If presente = False Then
            descrB.EntireRow.Copy Destination:=Rows(r + rngA.Rows.Count + 1)
            r = r + 1
        End If
        presente = False
    Next
    Windows(nomefile).Close
    Application.ScreenUpdating = True

    If r > 0 Then
        MsgBox "Totale righe importate: " & r
    Else
        MsgBox "Nessun dato importato; tutte le descrizioni corrispondono"
    End If
End Sub