hmm... I have never seen it done, and it might not be possible, considering the challenge-response concept.
Looking through [url=ftp://ftp.rfc-editor.org/in-notes/rfc2617.txt]RFC 2617[/url]
there may be a ray of hope:
To receive authorization, the client sends the userid and password,
separated by a single colon (":") character, within a base64 [7]
encoded string in the credentials.
