WinSCP failed to open saved session from command line

I would like to save site settings into INI file using portable version of WinSCP and reuse it from console or script file. By default WinSCP has saved session in format [Sessions\myuser@myhost.com], you can see on pic. 1. According to documentation I should open saved session with command
open myuser@myhost.com
But winSCP had trying to connect myhost.com and asked for password.

pic. 1

Using try-and-fail method I have found that session name should not contain @ . / characters, I have renamed session into myhost_com (pic. 2) and successfully open my stored session with
open myhost_com

pic. 2

Enjoy!