There is that NPC at Hunter's, Merlot or something... He has a variety of items, purchasable with Dimensional Coins. If i'm not mistaken, in other territories you earn them, just by participating to the Dimensional thingies with your clan. Something like participating in CoC, even if you don't kill anyone. How about Core?
Core has some issues to do Dimensional stuff... alone (yeah, the dimensional sieges and so on have their meaning by a temporal merge of servers, but lineage 2 EU is ONE server). That's why the dimensional raid quest was given to server population without having to do anything, that the PvP stone for dimensional sieges is given this way, and so on... So, I don't think those NPC or Coins will have any use.
