Is it possible to build an indicator simulating my account balance?

Shure, why not?

Use OrderOpenTime() OrderCloseTime() and OrderProfit() to get changes on your trading account for the history. Update on changes at OrdersHistoryTotal()

//z

there is something like this in the codebase already. It reconstructs not only the balance but also the account equity (or partial equity derived from trades in a certain pair only).

Thanks, I'll check in the codebase.