A little hard to tell from the brief description, but if you have 1 piece on your artboard and you are trying to duplicate it into cutting 2. What you do is do output to device and it should bring up a second window before starting. From there, there should be an option for how many you want to cut, put in 2 (1 should be default). Then in Copy options put the number in the correct X or Y spot (there should be a helpful popup on the left to help you determine where to put it), and hit output. Put the reader over the first mark it needs to read on the first part, have it read the entire part. When it gets to the second spot, do the same thing and it should register where it needs to cut on the table.