Imports System

Imports Microsoft.VisualBasic

​

Public Module Module1

    Public Sub Main()

        Console.WriteLine("* " & MaskFormat("123456787"))

    End Sub

​

    Function MaskFormat(input As String) As String

        input = input.Replace("-", String.Empty)

        If IsNumeric(input) Then

            If input.Length < 14 Then

                input = input.PadRight(14 - input.Length)

            End If

​

            Return String.Format("{000-000-000}", CLng(input))

        Else

            Return String.Empty

        End If

    End Function

​

End Module