Django, can't create app in subfolder

I'm on windows and trying to create a new app inside a common folder named Apps. The myApp folder already exists inside Apps. I'm running from the project root:

python manage.py startapp myApp Apps\myApp

and I get:

Error: 'Apps\\myApp' is not a valid app name. Please use only numbers, letters and underscores.

I don't know why that double backslash. I tried also with a forward slash just to be sure:

python manage.py startapp myApp Apps/myApp

and I get this:

Error: 'myApp' conflicts with the name of an existing Python module and cannot be used as an app name. Please try another name.

I can't understand if it is a Windows or a Python problem.