Option Strict On
Public Module CommandTest
   Public Sub Main()
      Dim arguments As String = Command
      If arguments = String.Empty Then
         Console.WriteLine("An empty string.")
      Else
         " handle command line argument(s)
         Console.WriteLine("Command line: {0}", arguments)
      End If
   End Sub
End Module 
Module Module1
    Sub Main(ByVal cmdArgs() As String)
        Dim strArg As String
        If cmdArgs.Length > 0 Then
            For Each strArg In cmdArgs
                Select Case strArg.Substring(0, 3)
                    Case "/a1"
                        Console.WriteLine("Processing arg1: Value is {0}.", _
                            strArg.Substring(3, strArg.Length - 3))
                    Case "/a2"
                        Console.WriteLine("Processing arg1: Value is {0}.", _
                            strArg.Substring(3, strArg.Length - 3))
                End Select
            Next strArg
        End If
    End Sub
End Module