It is all done as an intranet. There is (still) no connection to the outside (internet). It will probably happen in the future, but that's not what is going to happen right now.
Check
here for the representation i've done so far. On the left there are represented three machines and corresponding computers. Those machines send data to the computers through USB cables and a software running on the computer saves that data in text files (or not, it only saves if you hit 'Export'). The thing is, the same kind of product is being tested in three different machines and all data is separated from eachother logically and physically. The idea is to store all of that data under a unique ID to be consulted later on.
Fortunatly for me, there are some good news. The programs source is available and I'll probably be authorized to modify them.
It is not a case of data migration. Its about the storage of data each time the program receives data that comes from the testing machine.
Thank you both for your replies.