Hi.
If the password forms part of the URL it's easy to do, if not then you have a problem on your hands! Take a look at some of the MS investor supplied queries which come with Excel, if you edit the iqy file in something like notepad you will see you can prompt the user for information. There are also some further 'bits' after the URL in the iqy file, I wonder if you can specify here Password = "123" ? worth a try.
Failing this use XMLHTTP, this grabs the page for you, the problem here is you need to unscramble the data from the HTML - not easy but not impossible either.
Hope this helps