更好的代码：
Public Function cTon(ByVal sInNum As String, ByVal n As Double) As String
转换至n进制(n<=36)
欢迎交流，QQ：855000
  Dim dx As Double, iX As Long
  Const sNum As String = "0123456789ABCDEFGHIJKLMNoPQRSTUVWXYZ"
 
  If Not (Len(sInNum) > 0 And Len(sInNum) <= 15 And n > 0 And n <= 36) Then Exit Function
 
  dx = CDbl(sInNum)
  Do While dx > 0
    iX = dx - Int(dx / n) * n + 1           iX = dX Mod n +1 用Mod会溢出
    cTon = Mid$(sNum, iX, 1) & cTon
    dx = Int(dx / n)
  Loop
End Function

Public Function nToc(ByVal sInNum As String, ByVal n As Double) As Double
n进制转换至10进制(n<=36)
欢迎交流，QQ：855000
  Dim iX As Long, iY As Long
  Const sNum As String = "123456789ABCDEFGHIJKLMNoPQRSTUVWXYZ"
 
  If (n >= 2 And n <= 36) Then
    iY = Len(sInNum)
    For iX = 0 To iY - 1
      nToc = nToc + (InStr(1, sNum, Mid$(sInNum, iY - iX, 1), vbTextCompare)) * (n ^ iX)
    Next iX
  End If
End Function