Allowing a LAN only PC access to an external network IP via OPNsense Router

[Man Of Oblivion]

First off, I'm new to OPNsense, new to networking - that should guide you on your responses, and not just reply with use the search type answers, however, if there are basic underlying network concepts I would love to be directed there so that I may learn about them.

There is a network, user LAN (I'll refer to it as uLAN).  This uLAN does not have internet connectivity and I do not have control of this uLAN.  There is another network, my LAN (I'll refer to is as mLAN), which is one big SDWAN via the ZeroTier plugin.  My OPNsense device has two ethernet adapters, one plugged into a public ISP's modem which provides internet access to one big SDWAN via ZeroTier which is the mLAN, and another adapter plugged into the uLAN.  I need a PC on the uLAN to access the IP address configured on the OPNsense adapter on the uLAN and have that traffic redirected to an IP address on the SDWAN.

Let's say the OPNsense uLAN adapter's address is 192.168.1.45 and the uLAN PC's address 192.168.1.25 and the mLAN address of the actual server I need to access via the uLAN PC is 172.30.1.65.  I assume this is possible with OPNsense, I'm asking for some guidance on how & what to configure in OPNsense so that when the uLAN PC accesses the 192.168.1.45 IP the traffic actually ends up at 172.30.1.65.  The server at 172.30.1.65 is not a web server, it runs a custom application.  Bear in mind that I do not have control over the uLAN and can make no changes, I do control the OPNsense device that has an ethernet adapter physically connected to the uLAN.  Any help here would be greatly appreciated as I'm in the dark here as where to start, my knowledge level pretty much leaves me in the dark here.