Answer:
One option is to use the Windows property of the corresponding file. There, you will find information about when and by whom the file was created or modified (see Image 01).
A detailed view can be found in the "History" of the model, which you can open using the Project Manager (see Image 02). You can also find this information directly under General Data in RFEM or RSTAB (see Image 03). Automated retrieval of the data—for example, using a script—is not possible at this time.