Visual Basic.NET - leer unos archivos excels de una carpeta y pasarlos a formato pdf

Imports System.Collections.ObjectModel

Imports iTextSharp.text.pdf

Imports iTextSharp.text

Public Class Form1

    Dim fichero

    Dim files As ReadOnlyCollection(Of String)

    Dim ruta As String = "C:\Users\PEPE\Desktop\ficheros excel"

    Dim excel As Microsoft.Office.Interop.Excel.Application

    Dim carpeta_salida As String = "C:\Users\PEPE\Desktop\Nueva carpeta"

    Dim files2 As ReadOnlyCollection(Of String)

    Dim fichero2

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

        files = My.Computer.FileSystem.GetFiles(ruta, FileIO.SearchOption.SearchTopLevelOnly, "*.xls")

        files2 = My.Computer.FileSystem.GetFiles(ruta, FileIO.SearchOption.SearchTopLevelOnly, "*.pdf")

        excel = New Microsoft.Office.Interop.Excel.Application

        For Each fichero In files

            excel.WindowState = Microsoft.Office.Interop.Excel.XlWindowState.xlNormal

            ' My.Computer.FileSystem.CopyDirectory(ruta, carpeta_salida)

            If My.Computer.FileSystem.FileExists(carpeta_salida) Then

                My.Computer.FileSystem.DeleteFile(carpeta_salida)

            Else

            End If

            convertir_pdf()

        Next

        For Each fichero2 In files2

            My.Computer.FileSystem.MoveFile(fichero2, carpeta_salida)

        Next

    End Sub

    Sub convertir_pdf()

        Dim documentoPDF As New Document(PageSize.A4.Rotate, 100, 100, 100, 100) ' SE LE PONE LAS CARACTERISTICAS DEL DOCUMENTO PDF (TAMAÑO ETC.)

        iTextSharp.text.pdf.PdfWriter.GetInstance(documentoPDF, New System.IO.FileStream(fichero & ".pdf", System.IO.FileMode.OpenOrCreate))

        'documentoPDF.Open()

    End Sub

End Class

Private Sub Command1_Click()

    Dim cPDFCreator As clsPDFCreator

    Dim PDFName As String

    Dim PDFPath As String

    Set cPDFCreator = New clsPDFCreator

    Set cPDFCreatorOptions = New clsPDFCreatorOptions

    Set cPDFCreator.cOptions = cPDFCreatorOptions

    'Am storing default printer to restore it later

    strDefaultPrinter = Printer.DeviceName

    If cPDFCreator.cStart("/NoProcessingAtStartup") = False Then

            MsgBox "Can't initialize PDFCreator.", vbCritical + _

                    vbOKOnly, "Error!"

            Exit Sub

        End If

    With cPDFCreator

    .cOption("UseAutosave") = 1

    .cOption("UseAutosaveDirectory") = 1

    .cOption("AutosaveDirectory") = "C:\PDFTEST\test"

    .cOption("AutosaveFilename") = "Description du service.pdf"

    .cOption("AutosaveFormat") = 0    ' 0 = PDF

    .cSaveOptions

    .cClearCache

    .cPrinterStop = False

    .cDefaultPrinter = "PDFCreator"

    .cPrintFile "C:\PDFTEST\Description du service.doc"

     End With

    Printer.Print

    Set cPDFCreator = Nothing

    Set cPDFCreatorOptions = Nothing

    End Sub