Creation of Reference Frames on Part in SimScape Multibody

I am creating a SimMechanics model where I have certain components with several connection points on each component. In the first generation of SimMechanics it was easy to create these on the component. In SimScape multibody I can import the geometry as an STL as a geometry component, but then there does not seem to be an easy way to create the reference frames on the component itself. The options are either to create a reference frame on (i) the component reference (ii) CG or (iii) on a geometric entity, which does not exist if you import the geometry as a STL file. All I want to do is create a few hard points on the component. Any guidance would be appreciated.