Деление сверхбольших чисел - VB

'Сравнение 2-х положительных целых сверхбольших чисел в строковом формате 
 Function StrCompEx(m1 As String, m2 As String) As Integer 
   StrCompEx = Sgn(Len(m1) - Len(m2)) 
   If StrCompEx = 0 Then StrCompEx = StrComp(m1, m2) 
 End Function 
 
 'деление 
 Function div(m1 As String, m2 As String) As String 
 Dim dm As String 
 Dim i1 As Long, i2 As Long, L1 As Long, L2 As Long 
   L1 = Len(m1): L2 = Len(m2) 
   dm = Mid$(m1, 1, L2) 
   For i1 = 1 To L1 - L2 + 1 
     i2 = 0 
     While StrCompEx(dm, m2) >= 0 
       dm = dif(dm, m2) 
       i2 = i2 + 1 
     Wend 
     if dm="0"then dm=""
     dm = dm & Mid$(m1, L2 + i1, 1) 
     div = div & IIf(Len(div) = 0 And i2 = 0, "", i2) 
   Next i1 
 End Function
 
 'вычитание 
 Function dif(m1 As String, m2 As String) As String 
 Dim a() As String, n As Byte 
 Dim i1 As Long, i2 As Long, L1 As Long, L2 As Long 
   L1 = Len(m1): L2 = Len(m2) 
   ReDim a(L1) 
   For i1 = L1 To 1 Step -1 
     If L2 > 0 Then 
       a(i1) = Mid$(m1, i1, 1) - Mid$(m2, L2, 1) - i2 
       L2 = L2 - 1 
     Else 
       a(i1) = Mid$(m1, i1, 1) - i2 
     End If 
     If a(i1) < 0 Then 
       a(i1) = a(i1) + 10 
       i2 = 1 
     Else 
       i2 = 0 
     End If 
   Next i1 
   For i1 = 1 To L1 - 1 
     If a(i1) = "0" Then a(i1) = "" Else Exit For 
   Next i1 
   dif = Join(a, "") 
 End Function 
 
 'умножение 
 Function mul(m1 As String, m2 As String) As String 
 Dim a() As String, n As Byte 
 Dim i1 As Long, i2 As Long, L1 As Long, L2 As Long 
   L1 = Len(m1): L2 = Len(m2) 
   ReDim a(L1 + L2) 
   For i2 = L2 To 1 Step -1 
     n = Mid$(m2, i2, 1) 
     For i1 = L1 To 1 Step -1 
       a(i1 + i2) = Val(a(i1 + i2)) + n * Mid$(m1, i1, 1) 
       If a(i1 + i2) > 9 Then 
         a(i1 + i2 - 1) = Val(a(i1 + i2 - 1)) + a(i1 + i2) \ 10 
         a(i1 + i2) = a(i1 + i2) Mod 10 
       End If 
     Next i1 
   Next i2 
   mul = Join(a, "") 
 End Function