MACD HISTOGRAM in BackTest

For the MACD Histogram, I want to use it as a condition for a backtest. For example I want to write MACD_H(0)>MACD_H(1) (which would translate to MACD histogram today is greater than yesterdays. How can I program this into Amibroker?

SetTradeDelays( 1, 1, 1, 1 );
m = MACD();
BuyPrice = SellPrice =  Open;
Buy = m > Ref(m, -1);
Sell = NOT Buy;