You can't just "import" the process by the source code, because the computer needs to run something for the calculations. So you need to start 3 different softwares (Zorros) in this case.

But are you sure you can't do all these calculations in one script?

The best way for data exchange between processes (softwares) is the "inter-process communication (IPC)". The good news is that you don't need to write it yourself or find a C library, because Zorro has already implement this by "memory mapping", you just need to use the built-in commands - see the manual above. There is no simpler way.

Alternatively you can write&read txt files for data exchange, but I don't recommend it because there are a lot of ways to do it wrong, and it's much slower than IPC. Also, you can check the method called "named pipes", but it's complicated:
https://www.google.com/search?q=named+pipes+example+c
Before I found Zorro, I made MT4 EAs, and here's the library I used for the interprocess communication:
https://www.fxblue.com/appstore/9/quickchannel

But as far as I see, Zorro's built-in method is much better and simpler than these all.