The status buffer is just an interface to git; it's not an editor in itself, so you can't edit right from there. In Emacs, this isn't a problem, since you just RET and it takes you to the file/line/column you were at. There is still a feature request for this enhancement, but such functionality would be weird IMO since you'd have to enter some other mode within
magit-status-mode since most keys already mean something special.
You mention though that you want to use a different editor to edit this text. If that is your real question, read below.
If your editor supports command-line arguments, you can do this rather easily at a file-level by advising
(defun open-in-vscode (orig-fun &rest args)
(let ((file (car args)))
;; If you don't want this behavior for every file/project,
;; you can still keep the old behavior using `orig-fun`.
(if (or t (should-open-in-vs-code file))
;; This is VS Code, the only other editor I have installed
;; Look up Notepadd++'s arguments as appropriate.
"/Applications/Visual Studio Code.app/Contents/Resources/app/bin/code"
nil nil nil
(apply orig-fun args))))
(advice-add #'magit-diff-visit-file :around #'open-in-vscode)
If you want to jump to the file:line:column, you'll have to dig deeper into
magit-diff-visit-file and possibly provide a reimplementation (then advising using
:override) that will do the right thing for you. The line/column information is already available in
magit-diff-visit-file, so it would just be a matter of putting that information to other use.