Position Selection in MQL5: Unlike MQL4, MQL5 doesn't have PositionSelectByIndex(). You must use:
PositionGetSymbol(i) to get the symbol at index i
PositionSelect(symbol) to select a position by symbol
PositionSelectByTicket(ticket) to select by ticket
Commission Handling: In MQL5, commission is stored at the deal level, not the position level. To get the total commission for a position, you need to sum up the commissions from all deals related to that position.
Type Casting: When converting between numeric types, explicit casting is recommended to avoid warnings.
