Convert XLS to CSV on command line

A slightly modified version of ScottF answer, which does not require absolute file paths:

if WScript.Arguments.Count < 2 Then
    WScript.Echo "Please specify the source and the destination files. Usage: ExcelToCsv <xls/xlsx source file> <csv destination file>"
    Wscript.Quit
End If

csv_format = 6

Set objFSO = CreateObject("Scripting.FileSystemObject")

src_file = objFSO.GetAbsolutePathName(Wscript.Arguments.Item(0))
dest_file = objFSO.GetAbsolutePathName(WScript.Arguments.Item(1))

Dim oExcel
Set oExcel = CreateObject("Excel.Application")

Dim oBook
Set oBook = oExcel.Workbooks.Open(src_file)

oBook.SaveAs dest_file, csv_format

oBook.Close False
oExcel.Quit

I have renamed the script ExcelToCsv, since this script is not limited to xls at all. xlsx Works just fine, as we could expect.

Tested with Office 2010.

Open Notepad, create a file called XlsToCsv.vbs and paste this in:

if WScript.Arguments.Count < 2 Then
    WScript.Echo "Error! Please specify the source path and the destination. Usage: XlsToCsv SourcePath.xls Destination.csv"
    Wscript.Quit
End If
Dim oExcel
Set oExcel = CreateObject("Excel.Application")
Dim oBook
Set oBook = oExcel.Workbooks.Open(Wscript.Arguments.Item(0))
oBook.SaveAs WScript.Arguments.Item(1), 6
oBook.Close False
oExcel.Quit
WScript.Echo "Done"

Then from a command line, go to the folder you saved the .vbs file in and run:

XlsToCsv.vbs [sourcexlsFile].xls [destinationcsvfile].csv

This requires Excel to be installed on the machine you are on though.

How about with PowerShell?

Code should be looks like this, not tested though

$xlCSV = 6
$Excel = New-Object -Com Excel.Application 
$Excel.visible = $False 
$Excel.displayalerts=$False 
$WorkBook = $Excel.Workbooks.Open("YOUDOC.XLS") 
$Workbook.SaveAs("YOURDOC.csv",$xlCSV) 
$Excel.quit()

Here is a post explaining how to use it

How Can I Use Windows PowerShell to Automate Microsoft Excel?

A small expansion on ScottF's groovy VB script: this batch file will loop through the .xlsx files in a directory and dump them into *.csv files:

FOR /f "delims=" %%i IN ('DIR *.xlsx /b') DO ExcelToCSV.vbs "%%i" "%%i.csv"

Note: You may change extension .xlsx to .xls andname of script ExcelToCSV to XlsToCsv