How to set absolute sterechemistry in DS?

Dear all,
I've a set of molecures. I'am sure the sterechemistry is important for the activities of these molecures, so how can I set absolute sterechemistry for these molecures when building pharmacophore models of generating diverse conformations? Thanks in advance!

P.S. I created these molecures with ChemDraw with there sterechemistry properties and then I convert them into 3D structure with Chem3D. After these, I put all the molecures into a MSV file.