@MR.S 

Thank you so much. But i´m still not sure if i got it. 

Can we make a final example with the IPs from my screenshots to be sure that i unterstand it.

  @ChristianSchaaf 

It's not that easy for me to create a configuration for you based on some screenshots. You almost have to play around with routing a bit. What's important is that the OpenVPN Server IP POOL is routed, and that the Remote LAN is routed with the remote OpenVPN Sever IP as the destination, i.e. the IP that is in the VPN tunnel.

In my example, the router is OpenVPN both server and Client.
Use a full tunnel on the OpenVPN server that the PC connects to when you test, then you have one less problem.

  @ChristianSchaaf 

to confuse even more.
I did another test on another router, the router in my first example was an ER8411 where I had to add route to local openvpn server ip pool. when I do the same test against an ER707-M2 I don't need it. but it doesn't hurt to add it, I don't know how it is on ER605.

route to remote network 10.0.1.0/24 and 10.66.11.10/32 work even if I disable route to local OpenVPN server IP Pool