You can create a function to do this yourself:-
Code:
    Private Function FormatVersion(ByVal version As String) As String

        Return String.Join(".", From s In version.Split(".").Select(
                                    Function(value, index)
                                        If index = 2 OrElse index = 3 Then Return value.PadLeft(4, "0"c)

                                        Return value
                                    End Function))

    End Function
Tested with this:-
Code:
Debug.WriteLine(FormatVersion("1.2.430.20"))
Produces this output:-
Code:
1.2.0430.0020