'Imports Excel = Microsoft.Office.Interop.Excel
Dim loadpath As String = IO.Path.Combine(Application.StartupPath, "file.xls")
Dim savepath As String = IO.Path.Combine(Application.StartupPath, "file.csv")
Dim app As New Excel.Application
app.DisplayAlerts = False
Dim book As Excel.Workbook = app.Workbooks.Open(loadpath)
book.SaveAs(savepath, Excel.XlFileFormat.xlCSVWindows)
book.Close()
app.Quit()