for your first question, if you aer using Non-sequental Mode then you could find MEMs directly under the NS object list, The DLL version is used in sequential mode alone! K=`;D
1__Mf.A
For your 2nd Q, like the upstairs's reply, the STEP files should be saved under ZEMAX\Objects\CAD Files. b08s610fk
2UGnRZ8:1Y
Hope this would help :)