Using Nextcloud with IIS reverse Proxy

NethServer Version: 7.3.1611
Module: Nextcloud

Hello everyone,
I have a small problem using the Nextcloud with a reverse Proxy.
I have a Windows Active Directory with Windows 2012R2 Server and use the Nethserver as Nextcloud-Server.
I also have an Exchangeserver and using the OWA via IIS reverse Proxy.
I used this tutorial to configure the IIS as reverse proxy
Reaching the Apache default site is no problem via nextcloud.domain.tld, but I cant reach the nextcloud via nextcloud.domain.tld/nextcloud
Chrome shows “ERR_TOO_MANY_REDIRECTS”-error.
Is there any way using the nextcloud via a reverse proxy?

I tried a configuration with 2 Nethservers. The Frontend with Nethserver and ReverseProxy and in the Backend a Nethserver with LDAP and Nextcloud.
Reverseproxy to the mainpage of the Backendserver is no problem, but I cant figure out how to access Nextcloud via Reverse Proxy.
Is there any HowTo for this config?

Check this out:

I already tried this, but it doesnt work.
When I try to access the NC via LAN, the Module rewrites the LAN IP of the NC with the reverse proxy IP.
When I try to access the NC via reverse proxy, the Module does not rewrites the IP, so the reverse proxy show the LAN IP.
So I cant access the NC in any way.