EDIT: I have found a solution, I'll post it here, as I can't answer my own question yet. Not enough reputation, I have to wait 8 hours.
I found a workaround, by using VirtuaBox and Windows. I asked VirtuaBox to host the disc drive, and I could access the file just fine from the virtual machine. I hope this helped!
I have received a disc with a program I have to install.
The problem lies in the fact that I have to access a .txt file which contains the program's serial it – it's a personal back-up copy – and I do remember that this file is inside the disc.
The problem is that the serial can be seen and opened from Windows, but not from the Mac, which shows its own "version" of the disc: that is, the readme file, and the applications to install the software. And nothing more.
My question is, is there any way to access this disc as if I were reading it from Windows? That is, displaying the actual file system, without those Mac-only options?