Getting Transmission Data from a Host Computer into a Login System

I am working with a relative who owns a small medical testing lab. He currently has a WordPress website.

He has testing machines that feed results into a host computer, which then sends the results in table/CSV type format, to a third-party company/website that allows my relative to create login information for clinic managers to login and see the test results as they come in.

He wants to bring this whole process into to his WordPress website (or at the very least make it appear that these clinic managers/doctors are on his WordPress site still).

Requirements would include:
-A way to pull in the data from the host computer
-Display the data behind a login wall
-Have data on test results be displayed only to specific users, while other data is private from other users. Master admin can access all result data

Does anyone have any idea where I start with this?

There is some documentation from the test machine company, but it focuses mainly on the setup of the test results going to the host computer. Nothing on getting that info to a login site.

Any help or tips of any kind would be greatly appreciated!