Add Arena Coin Drop ?!

Hey guy`s
U can help me ?
I wann add ArenaCoins as Drop to all Mobs on server!
How i can do this?

_RefDropItemAssign
I have add the Coins... But what AssignedGroup it need?

And where i can config then the Drop rate?

_RefDropClassSel_Alchemy_??????

Or give it a better way ?

???

???

_RefMonster_AssignedItemDrop