From the following Microsoft support document:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q311731

I am able to see how you can query an Excel file through ASP.NET.  The
only problem is, this approach requires that the Excel file be
available as a locally accessable file, like C:\datafile.xls.  The
datafile I want to retrieve is on the internet, such as
http://www.dummysite.com/datafile.xls (example name only, not a real site...)

I'm able to use the WebRequest and StreamReader to read the Excel file
as a binary stream, but then I have to save this somewhere locally and
open the saved file.  I want to be able to read the file and directly
be able to use that file as my data source to query without writing
anything to the local server.  Could you show me how this can be done
using VB.NET?

Your looking at it the wrong way.
There are database drivers which allow you to open a Excal (or csv for
that matter) file as a database.
Search around for the correct connection string. It will have excel in it.

I know this.  The problem is that you have to access a local file, and
not a file on the internet.

Try writing the full URL of the online Excel file in the
Server.MapPath() inside the connection string

Would that such a simple, elegant solution would work...but alas, it does not.

You mean, there should be user web userinterface to load excel file
and then pull data from the loaded excel at run time. am i correct?

Exactly.

You can't use Excel file located on remote HTTP server as datasource
because HTTP knows nothing about file's format - it treats all files
equally and can only give you it's MIME type in "Content-type" header.

You have two options:
1. Download Excel file to temporary folder, read it as database and
delete it afterwards.

2. IF you have ability to put scripts to remote server, then implement
reading functionality on that remote server and send DB requests to
remote server through CGI-protocol getting results in response body
(as XML for example). This can be done as web service or as simple web
page.

    Sergey.

That's what I know as of now, and due to project requirements and
security restrictions I'm not happy with either option.  I was hoping
there was a way to read the file into memory and treat that memory as
if you were using a file somehow.  Basically the same as creating and
deleting a temporary file, except without actually creating the
temporary file.

Hi, hailstorm-ga:

Have you considered using a small RAM disk for this purpose?

regards, mathtalk-ga