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! 2l}3L
bdyIt)tK+
For your 2nd Q, like the upstairs's reply, the STEP files should be saved under ZEMAX\Objects\CAD Files. $`txU5#vs
x<>In"QV
Hope this would help :)