Different shell for different users

I read the article "Different Shell for different Users" (
http://msdn.microsoft.com/en-us/library/ms838576.aspx ).

I would like to have a custom shell for all users, and the normal
explorer shell, with taskbar, only for one user.
So every new user added to the system will have my custom shell.

I changed the system custom shell changing the key2 HKEY_LOCAL_MACHINE
\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell from
Explorer.exe to my custom shell.

and I set the key3 HKEY_Current_User\Software\Microsoft\Windows NT
\CurrentVersion\Winlogon\Shell with Eplorer.exe for one administrator
account.

So everything works as I want, but the administrator account with the
key3 uses explorer but doesn't have the taskbar!
I need taskbar too, with explorer shell.

How may I have the normal explorer shell WITH TASKBAR for a single
user (current user shell) and how may I have my custom shell for all
other ones, as system shell?

Best regards,

Francesco Gigante