The main format Medium uses for import is OBJ. If your cad software can export to OBJ then you should be able to import it.
Although be aware that Medium isn't a mesh based editor/viewer, it uses distance fields (which is how it does solid clay modelling instead of triangle meshes). So what you import isn't going to look exactly the same, detail may be lost or changed. If you just want to see an existing scene in VR then the best way is using Unreal or Unity (Unreal being easier if you aren't a programmer). They can understand a few formats, or you can use a program like Blender to convert.
Just to add on to what @kojack has said, Unreal Engine is indeed the easiest way. If you install the latest Unreal Studio which is free, make sure to register as Enterprise.
The latest version of Unreal has a feature called DataSmith ... it allows to easily import entire scenes from many CAD applications directly into Unreal.
