"title" frame param: Want "string %f %b" with string different for some frames

[Allan Gottlieb <gottlieb@nyu.edu>]

If I want the frame to have a unique title I use

(modify-frame-parameters nil '((title . "sam")))

Which works fine, making the title "sam".

Since I like the title to contain %b %f (buffer and file names), I
have in my .emacs

  (setq frame-title-format '("Emacs: %b <%f>")))

which also works fine.

I would like a combination of the two and am having trouble.

Say I want the current frame to have "sam" in the title together with
the current file and buffer names, I would like to say something like

 (setq current-frame-title-format '("sam: %b <%f>")))

and have all other frames still use  '("Emacs: %b <%f>")))

Any help would be appreciated.

thanks,
allan