open-to-close price is the difference between Open Price and Close Price when the trade was closed, so you should use "For each Closed Trade" here. Otherwise I think that Close Price is the current price, if not 0 (I don't remember exactly).
Both prices are the real prices where the trade opened and closed, so the spread is probably somewhere in there. Well, not the current spread, but the one that was in those events.
The spread is available somewhere else in Condition, somewhere under Market properties again as price fraction (ask - bid). Otherwise as MQL4 code it is:
MarketInfo(Symbol(), MODE_ASK) - MarketInfo(Symbol(), MODE_BID)
But do you really need that...
There is something else, but this returns points which are probably not really useful in fxDreema. If the spread is 2 pips, it will return 20 🙂 Again, if I remember correctly 🙂
MarketInfo(Symbol(), MODE_SPREAD)