Remote Windows Update using Powershell to a air-gapped server

My setup has a Windows 10 Desktop that runs "Windows Admin Software" to manage a directly connected Dell Server. This set up is functioning smoothly. The Desktop is connected to Internet.

The challenge is that this server is (and, desirably be) NOT connected to Internet as that is not required. The purpose of the server is to run extremely CPU intensive scientific computations. But then, updating that server OS (running Windows Sever Core 2016) becomes a problem.

Is there a way I can check remotely (from the desktop logged into the server) what updates are available, and then update those using the Internet access at the Desktop itself. If so required, am happy to do a "manual" download to the Desktop, then do a copy to the server, and then install the msu manually.

Exploring a better solution than connecting the server to Internet once in a while and doing a update command from the Windows Admin Centre running on Desktop.

Thanks