Not really. We make it a point not to do this. The only peeking allowed is the TradeInsideBars flag which will allow your backtesting to see the close value of the current bar which is technically cheating.
Is it possible to let user make some kind of "peeking" (while backtesting). I mean the possibility of use negative parameter in Lookback property ( after setting SystemData.TradeInsideBars to true, for example).
Without this 'feature" some kind of systems are very hard to write or are not possible to write at all.
Like dr Koch wrote in one of his posts: "Yes, I know this is not realistic, but it is a quick way to backtest strategies which otherwise would need much more and much more complex programming"