Outlook does not do that.
Create a Contact with whatever name you want and put it in the To: field.

Signature
Russ Valentine
[MVP-Outlook]
> Many times I see messages which have "undisclosed-receipient" displaying
> in
> the "to:" box. I know about "Bcc:" filed but using that shows the senders
> address in the "to:" box. How to create this "undisclosed-recepient" list
> in
> MS Outlook?