[amibroker] Problem Adding A Custom Metric

[ian_rosbif]

I'm trying to add a Backtester column to show an indicator value at 
trade entry. Using examples taken from elsewhere on the forum, I came 
up with the code below. However, "test2" is always 0.00. Can anyone 
tell me where I'm going wrong? Thanks.

AddToComposite( CCI
(14), "~UI_HISTORICAL", "X",atcFlagEnableInPortfolio+atcFlagDefaults )
;
// Custom Backtest
SetCustomBacktestProc("");
if (Status("action") == actionPortfolio){
    bo=GetBacktesterObject();
    bo.Backtest(1);
    dt = DateTime();
    bi = BarIndex();
    for (trade = bo.GetFirstTrade(); trade; trade = bo.GetNextTrade())
    {
        SetForeign( trade.Symbol ); // need to switch the symbol
        entrybar = LastValue( ValueWhen( dt == trade.EntryDateTime, 
BarIndex() ) );
        SetForeign( "~UI_HISTORICAL" ); // need to switch the symbol
        test2 = C[ entrybar ]; // we need scalar value 
        trade.AddCustomMetric("test2",test2);
    }
    bo.AddCustomMetric("Marker","Marker");
    bo.ListTrades();
}