How to encrypt plain text document .txt?

Question

Passwords

Without any programs, etc., well, let's say it's possible through a batch file. And that no one could ever open this file.

Answer 1

And the program can be run from a bow?

Answer 2

Without any programs, etc., well, let's say you can through the batch file

Batch file - there is a list of commands. command = program. And the composition and parameters depend on the OS and its components.
And to read txt, you also need a program.