I want to write an interactive function that finds an arbitrary file
from a specific directory "~/org"
The following attempts do not work but should give the idea what I am
trying.

(defun startorg(file)
(interactive "FFile: ")
(let ((default-directory "~/org"))
(find-file file)
))

(defun startorg(file)
(cd "~/org")
(interactive "FFile: ")
(find-file file)
)

The general problem can be stated as:
I want to write an interactive command

What Ive done for now is this. Dont know if its the proper idiom

(defun startorg(file)
(interactive
(let ((default-directory "~/org/"))
(list (call-interactively 'find-file))
)))

Dont know how its working given that the parameter file is not used!

rustom gmail.com> writes:

(interactive (list (read-file-name ...)))