How do I use a ConnectPort WAN VPN as a switch to communicate between a local computer and another local ethernet device

Hope this is the right place for this. (Support shows it as an active product, but all search results reside in support.). Any better category suggestions are welcome. I ask forgiveness for any newbie trangressions in advance…

I have several mobile embedded PC’s and paired with an equal number of ConnectPort WANs. The function of the PC is scientific in nature, collecting and collating data from several RS232/485 serial sensors. The function of the CP WAN is primary data transmission with iridium satellite backup. The PC has 2 ethernet connections. One is connected to the CP WAN, the other is unused.

I have new radiation detectors that have an ethernet interface. I would like to communicate locally betwen the PC and a single detector using the CP WAN as a switch, so to speak. This would leave me with 1 available ethernet port on the PC and 2 on the CP WAN for future use.

I’ve waded through hours of CP WAN documentation and KB articles without even finding the terminology to describe what I would like to do.

Is this ‘doable’ and what is it called, so that I may drill down on it?