How to get source for MA in different time frame?

Hello @Spotware / @Panagiotis / Anyone:

I want to be able to allow the user to select the source (high, low, open, close) for their EMA that's in a different time frame.

        [Parameter()]
        public TimeFrame SourceTimeFrame { get; set; }

        [Parameter("Fast Period", Group = "Fast MA", DefaultValue = 55, MinValue = 1)]
        public int MAFastPeriod { get; set; }
        [Parameter("Fast Type", Group = "Fast MA", DefaultValue = MovingAverageType.Exponential)]
        public MovingAverageType MAFastType { get; set; }
        [Parameter("Fast Source", Group = "Fast MA")]
        public DataSeries MAFastSource { get; set; }

private Bars _marketSeries;
private MovingAverage _movingAverageFast;

        protected override void Initialize()
        {
            _marketSeries = MarketData.GetBars(SourceTimeFrame, Symbol.Name);


//this is the part that is giving me trouble. How do I set the _marketSeries.HighPrices,
// .ClosePrices, .LowPrices, .OpenPrices to whatever the user selects as the source 
//from above?
//Right now, it's just coded as ".ClosePrices" as you can see below.
            _movingAverageFast = Indicators.MovingAverage(_marketSeries.ClosePrices, MAFastPeriod, MAFastType);

}

Thank you.