Thanks … I got the point. It is svchost.exe that is displayed because it is a scheduled job. I did not realize that.
I can make a job run minimized starting like this:
http://www.webyog.com/faq/27_74_en.html
When you have created the shortcut you can right-click it and from the 'shortcut' tab choose 'run as minimized' (what it is exactly in English I don't know – but something similar!) It works fine here.
But I have not succeeded in trying to run a scheduled job minimized. I don't know if it can be done when scheduling a command-line tool like SJA at all. An attempt to schedule a shortcut fails here.