did some research on this, but could not find a solution working for this single-server-enviroment without DC and AD. The users in question are members of "local-non-admins" and "remote users".
The available gpo with logon-/logoff-scripts-options apperently does not work when logging in as "remote user".
Any hint on where to start further digging is highly appreciated.
Regards
Karl
After some more research I finally found out, that the login-scripts from GP do work for remote-users, you just have to allow remote-users to execute those scripts (which is not done by default when just creating simple scripts with notepad).
Hope it helps someone else.