RDP Shadow Mode: How to pass CTRL+ALT+DEL to remote?

I have set up RDP shadow mode on a remote Win Server 2003 server per the
configurations instructions at the end of this email. I can remote into the
server, then shadow the console session fine from my Win XP network client.
However, I am unable to pass CTRL+ALT+DEL to the remote to unlock the
server. (This server always remains in lock mode; not logged out.) I also
tried CTRL+ALT+END but that doesn't work either. How can I pass CTRL+ALT+DEL
to the remote in console shadow mode? Ultimately I want to be able to unlock
the current console session and work from that session. Thanks.

RDP Shadow Mode Configuration:
Configuring Terminal Services on the Win2003 Server

1. Log into the server, choose Start, Programs, Administrative Tools,
Terminal Services Configuration

2. In the left pane, select Connections. Then in the right pane double click
RDP-Tcp.

3. In RDP-Tcp Properties, choose the Remote tab. Click Use remote control
with the following setting, uncheck Require user's permission, click
Interact with session. Choose OK.

Configuring Group Policy for Terminal Services on the Win2003 Server

1. Click Start, Run. Type gpedit.msc in the Open field and click OK. This
opens the group policy editor.

2. Under Computer Configuration, expand Administrative templates, expand
Windows Components, and then click Terminal Services.

3. Right-click Sets rules for remote control of Terminal Services user
sessions, and then click Properties.

4. Select the Enabled option.

5. Under Options, click Full Control without user's permission.

6. Click OK, and then quit Group Policy Editor.

To update the local policy immediately afterward without having to reboot,
go to a command prompt and run the following command: gpupdate /force

Once you've got all this set up, to actually use it to shadow the console
session where the programs are running:

1. RDP into the server.

2. Open a command window.

3. Enter: shadow 0 and then press ENTER. This will shadow the console
session.

If you want to shadow a different session, you can enter the query user
command and get a list of user sessions. Entering session 'n' where 'n' is
the user session will put you into shadow mode on that session.