Uhm, if I remember correctly you can create .dmg or .iso files from the original CDs before mounting them as sudo discs that acts in the same manner as having the original CDs plugged into you laptop.
Now if you don't have any device that has a CD drive, you could either ask a friend who does or like you said somehow download it from somewhere.
Officially we can't condone piracy of any kind even with plausible legitimate excuses or give you advice on how to do it as it can lead to other third party readers to obtaining the game illegally through the same steps. What I can advise you is to use search engines like Google to find a reliable source or collection of information and then see if they have what you need, just like what you tried to do here. ^_^
PS I'm not sure about the situation about the SafeDisc 2 but I digitalised my entire CD collection and my 3 CD disc set of Red Alert 2 in .iso format does work on my MacBook Pro late-2011 model using Yosemite OS X.