What i want: custom field article id, with search by articles list.
Now I can only store the articles IDs in the string and then manually process it on the product page.
But it is inconvenient.
Now I have to figure out the material numbers in advance. I would like to choose them from the list
I dont have completly understand your problem, but my plugin Shortcodes can display a Joomla article
See https://shop.st42.fr/en/products/shortcodes.htm and demo http://pro.st42.fr/en/shortcodes/all-shortcodes-2400.html that display some of shortcodes features.