3dc and cad file to open?

Hello guys! I’m Igor! I’m new in this community. Searching for help. Does any body know how to open file in 3dc or cad , using MAC ? The goal is : I’ve made picture of portrait of myself in 3d. It was not made by 3D scanner, it was one of those service , you can see some times in the MALL or some other places, Where they print 3D image in glass cube. I’ve asked to save file on the stick drive. I need to open it and to make some modification, and save it in STL format for 3D printer. I have Solid Works, but it can’t open it. So any help or suggestions appreciate. Igor. Please use my e mail, so easy for me with out log in, to watch your response.