How To Open Another Workbook That Is Password Protected

Code:
Sub Open_Test_File()
Dim wb As Workbook
Set wb = Application.Workbooks.Open("DesktopTest File.xls")
End Sub

This very simple little code opens a new workbook.

But if I add a password to the file that I'm going to open the password box appears.

What do I need to add to this code to automatically input this password?

I have tried putting this at the end:

Code:
Password:="123"
but this does not work?