How make Dired open selected files in a SPECIFIC window when there are multiple windows?

[Tak Kunihiro]

You can freeze the Dired window.

(global-set-key (kbd "C-x 9") 'freeze-window)
(defun freeze-window ()
  "Freeze or lock a window where point is.  Call again to unfreeze.
Technically this toggles window-dedicate-p property of a window."
  (interactive)
  (let ((frozenp (window-dedicated-p (selected-window)))
        (win (selected-window)))
    (set-window-dedicated-p win (not frozenp))
    (message (format "%s is %s" win (if (not frozenp) "frozen" "free")))))


> I'd like to keep a small Dired window open that I can keep selecting
> files from, and, have them all open in a specific big window.
> 
> (I'm basically trying to mimic an IDE where you have a "file chooser" widget.)
> 
> How do that?