Placing penetrations on the right Part definition

Hello,

I have a custom dataset in which I want to place slab/and floor penetrations.

I managed to copy some files from the Dataset_NM, so now I can select the right PAZ-cells with the 'Place wall or slab penetrations' tool. I also made a part definition  'Doors-Windows-Openings: Opening'

When I do it in the delivered dataset 'Dataset_NM' automatically the part 'Doors-Windows-Openings: Opening' is chosen, but I can't seem to configure it in my own workspace/ dataset. Can someone tell me where it's defined?

regards,

Jean-Paul