bu fonksiyon ile yeni ismi buluruz

Function renameSheet(lastSheetName As String, lastId As Integer, Optional ayrac As String = "_") As String
    Dim realSheetName As String
    Dim newSheetName As String
    Dim lastUnderlineIndex As Integer
   
    If (InStrRev(lastSheetName, ayrac) > 0) Then
        lastUnderlineIndex = InStrRev(lastSheetName, ayrac)
        realSheetName = Left(lastSheetName, lastUnderlineIndex - 1)
        newSheetName = realSheetName & ayrac & lastId
    Else
        newSheetName = lastSheetName & ayrac & lastId
    End If
   
    renameSheet = newSheetName
   
End Function