So for some reason you have the need to use vbscript (maybe a .vbs file, Excel script, etc) but like many others before you, you have run into a limitation of vbscript. I’m not going to discuss the reasons why / why not to use vbscript, I am already assuming you have a good reason. Onto the example. In this case, we are “fixing” the limitation of vbscript to not handle larger numbers well. We are going to extend our vbscript by creating a .dll library in Visual Studio that allows us to pass and return data in the format we need, in the example case, to round a large decimal number.

1. So let’s first fire up Visual Studio and create a “Class Library”. In my case I called it: sampleMathLibrary and used vb.net.
2. In the AssemblyInfo.vb, set this to be true: <Assembly: ComVisible(True)>
3. Toss in some functions:

   Imports System
   Public Class mathLibrary
   Public Function roundNumber(number As String) As String
   Dim roundedNumber As String = ""
   Dim largeNumber As Decimal = 0
   If IsNumeric(number) Then
   largeNumber = Convert.ToDecimal(number)
   roundedNumber = FormatNumber(largeNumber, 0, TriState.UseDefault, TriState.UseDefault, TriState.False)
   End If
   Return roundedNumber
   End Function
   End Class

4. You need to register your .dll for use in vbscript, so using the regasm tool, run this:

   regasm C:\PathToYourDll\samplemathlibrary.dll  /codebase

5. Now create / update your vbscript to utilize the “CreateObject” and your new functions:

   dim mathLib
   set mathLib = CreateObject("sampleMathLibrary.mathLibrary")
   Dim num
   'some huge number
   num = 4895390000000005
   'just to see how vbs would handle - WRONG
   msgbox(FormatNumber(num,0,-2,-2,False))
   'now fix for our function
   num = "4895390000000005"
   'so good
   msgbox mathLib.roundNumber(num)

That’s all you need. Sure, it’s not pretty, but if you have legacy code that needs to be extended, the sky is the limit!