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! *CH lg1
?r,lgaw
For your 2nd Q, like the upstairs's reply, the STEP files should be saved under ZEMAX\Objects\CAD Files. Z ?{;|Z5
\HzI*|*A
Hope this would help :)