"Henrikinpoika" or "Heikinpoika" means "Henrik's son" so probably his father's name was Henrik or Heikki. Your great-grandfather could also have been called "Anders Vilhelm Henriksson" if he lived on the Swedish side (the area of Sweden near the Finnish border is traditionally a Finnish-speaking area, but "officially" Swedish) or if the Finnish records were in Swedish (not sure if they were in 1846).
Here is a little about Karunki/Karungi:
http://www.renne.com/Maternal/Jacob1.htmlI have no idea where the "Mandaringet" could be, it's probably an English-speaking person's interpretation of a Finnish name. It looks a bit like Matarengi, which is quite near Karunki. Or it could be the name of the house/homestead he was born in, which would make it easier to find relatives of him.
Now I'm curious what "Mandaringet" could be (my family is from that general area as well, though not from Karunki), so I posted a question in a Swedish forum about it, I'll get back to you if I find out anything.