I contacted them via their website form. I asked for Status Match from Miles & More Senator or Krisflyer PPS to Finnair Plus Gold but it was declined with the following (rude) answer. Surely I can send proof but I did not via this first contact.
Dear Christoph,
thank you for your e-mail.
Unfortunately we have no status match.
You may earn the points from Basic-level.
Have a nice day.
Best wishes
Finnair Plc
Finnair Customer Care