Reference selectors allow you to set a selection page. This basically allows you to do exactly what you need, the only downside is that you need to open an extra popup page to do the selection/search.
Joost,
One approach you could take:
You could also accomplish this using the Listview in your page in a similar fashion. Listview enables you to set a microflow that is invoked on click. The advantage of the listview, IMO, is the combined search box which can search multiple fields at once and resolves searches as the user types.
One other idea - there is an Input Reference Selector widget in the appstore that might work for this. I have not used this widget in a scenario where there are millions of products so I don't know if you would run into performance issues due to the large number of records.
Hope that helps,
Mike
Hi Pieter and Mike, the selection Page on the reference selector was exactly what I was looking for, thanks for your kind help.