Routing between LANs

Sonicwall SOHO250.

X0 is corporate LAN, subnet 192.168.22.0, interface at 192.168.22.1

X1 is WAN

X2 has an Ethernet cable connected to an internet modem (separate internet service from the Sonicwall X1) that services customer WiFi. Subnet 192.168.1.0, interface at 192.168.1.1

I do not want customer WiFi traffic going through the Sonicwall; it goes straight to the modem and out to the internet. But I need a way to get to that modem's LAN interface for management/reboot purposes from the corporate LAN, that is, without having to connect to the customer WiFi network.

I created a separate ModemLAN zone for that interface & subnet. Sonicwall X2 IP is static on 192.168.1.2. I added the firewall rule allowing everything to go from (corporate X1) LAN to ModemLAN but not allow customer WiFi ingress to the corporate LAN (i.e. not ModemLAN to LAN...