Accessing Internal Web Server With WAF & Split DNS

Question

We currently have an internal IIS server, that is hosting a website, published via WAF, that is working externally and internally, as we haven't had split DNS set up for it. I want to create a new zone, to setup split DNS but how can I then get internal users to access it using WAF? Or do I have to use NAT? 
 Thanks in advance. 
 Michael

traxxus · Answer

Step 1: 
 Copy the existing WAF rule (under Virtual Webserver) and change the interface to your LAN interface (Internal) 
 Step 2: 
 Create a DNS -A-record on your DNS server which points to the UTM IP.