You don't need the time crunch headache of a custom coded WP at this point. What Mark posted is a good idea, use the operating system's like Notepad (default) or Wordpad, for now. If you want to use Wordpad, just be sure you save it as regular text, that means use a .txt suffix. The rtf of Wordpad would mess up your database big time. Notepad has almost no bells and whistles and no spell checking, but it will always save as .txt. Anyway, to try Wordpad, you would do a shell as:
SHELL "wordpad " + CHR$(34) + "test file edit test.txt" + CHR$(34)
I usually use CHR$(34), the qute character, to offset the sometimes problem of spaces occurring in a file name. Actually, I usually avoid using spaces in a file name, and just put hyphens in place of a space.
Also note that QB64 can use SHELL _DONTWAIT if you ever want your program to continue before the app it opened with shell is terminated. Without _DONTWAIT your QB64 app will be suspended until the app it opened is closed. So if you mess up a SHELL call without using it, you might need to open task manager to close out your QB64 exe file as the app being shelled to will fail to open, but the QB64 app running won't know that! It will just stay open, in a suspended state, waiting for you to close an app that you can't close, because it never opened. Anyway, just a heads up.
Pete