VBA Code for excel Number to words Convert Formula

Function NumToWord(ByVal N As Currency) As String

   Const Ten = 10@
   Const Hundred = Ten * Ten
   Const Thousand = Ten * Hundred
   Const Lakh = Thousand * Hundred
   Const Crore = Lakh * Hundred
   Const Million = Thousand * Thousand
   Const Billion = Thousand * Million
   Const Trillion = Thousand * Billion

   If (N = 0@) Then NumToWord = "zero": Exit Function

   Dim Buf As String: If (N < 0@) Then Buf = "negative " Else Buf = ""
   Dim Frac As Currency: Frac = Abs(N - Fix(N))
   If (N < 0@ Or Frac <> 0@) Then N = Abs(Fix(N))
   Dim AtLeastOne As Integer: AtLeastOne = N >= 1

   If (N >= Crore) Then
      Buf = Buf & NumToWordDigitGroup(Int(N / Crore)) & " Crore"
      N = N - Int(N / Crore) * Crore
      If (N >= 1@) Then Buf = Buf & " "
   End If

   If (N >= Lakh) Then
      Buf = Buf & NumToWordDigitGroup(Int(N / Lakh)) & " Lakh"
      N = N - Int(N / Lakh) * Lakh
      If (N >= 1@) Then Buf = Buf & " "
   End If

   If (N >= Thousand) Then
      Buf = Buf & NumToWordDigitGroup(N \ Thousand) & " Thousand"
      N = N Mod Thousand
      If (N >= 1@) Then Buf = Buf & " "
   End If

   If (N >= Hundred) Then
      Buf = Buf & NumToWordDigitGroup(N \ Hundred) & " hundred"
      N = N Mod Hundred
      If (N >= 1@) Then Buf = Buf & " "
   End If

   If (N >= 1@) Then
      Buf = Buf & NumToWordDigitGroup(N)
   End If

   NumToWord = Buf
End Function

Private Function NumToWordDigitGroup(ByVal N As Integer) As String

   Const Hundred = " hundred"
   Const One = "one"
   Const Two = "two"
   Const Three = "three"
   Const Four = "four"
   Const Five = "five"
   Const Six = "six"
   Const Seven = "seven"
   Const Eight = "eight"
   Const Nine = "nine"
   Dim Buf As String: Buf = ""
   Dim Flag As Integer: Flag = False

   Select Case (N \ 100)
      Case 0: Buf = "": Flag = False
      Case 1: Buf = One & Hundred: Flag = True
      Case 2: Buf = Two & Hundred: Flag = True
      Case 3: Buf = Three & Hundred: Flag = True
      Case 4: Buf = Four & Hundred: Flag = True
      Case 5: Buf = Five & Hundred: Flag = True
      Case 6: Buf = Six & Hundred: Flag = True
      Case 7: Buf = Seven & Hundred: Flag = True
      Case 8: Buf = Eight & Hundred: Flag = True
      Case 9: Buf = Nine & Hundred: Flag = True
   End Select

   If (Flag <> False) Then N = N Mod 100
   If (N > 0) Then
      If (Flag <> False) Then Buf = Buf & " "
   Else
      NumToWordDigitGroup = Buf
      Exit Function
   End If

   Select Case (N \ 10)
      Case 0, 1: Flag = False
      Case 2: Buf = Buf & "twenty": Flag = True
      Case 3: Buf = Buf & "thirty": Flag = True
      Case 4: Buf = Buf & "forty": Flag = True
      Case 5: Buf = Buf & "fifty": Flag = True
      Case 6: Buf = Buf & "sixty": Flag = True
      Case 7: Buf = Buf & "seventy": Flag = True
      Case 8: Buf = Buf & "eighty": Flag = True
      Case 9: Buf = Buf & "ninety": Flag = True
   End Select

   If (Flag <> False) Then N = N Mod 10
   If (N > 0) Then
      If (Flag <> False) Then Buf = Buf & "-"
   Else
      NumToWordDigitGroup = Buf
      Exit Function
   End If

   Select Case (N)
      Case 0:
      Case 1: Buf = Buf & One
      Case 2: Buf = Buf & Two
      Case 3: Buf = Buf & Three
      Case 4: Buf = Buf & Four
      Case 5: Buf = Buf & Five
      Case 6: Buf = Buf & Six
      Case 7: Buf = Buf & Seven
      Case 8: Buf = Buf & Eight
      Case 9: Buf = Buf & Nine
      Case 10: Buf = Buf & "ten"
      Case 11: Buf = Buf & "eleven"
      Case 12: Buf = Buf & "twelve"
      Case 13: Buf = Buf & "thirteen"
      Case 14: Buf = Buf & "fourteen"
      Case 15: Buf = Buf & "fifteen"
      Case 16: Buf = Buf & "sixteen"
      Case 17: Buf = Buf & "seventeen"
      Case 18: Buf = Buf & "eighteen"
      Case 19: Buf = Buf & "nineteen"
   End Select

   NumToWordDigitGroup = Buf

    End Function