I do not trade Forex, but the following found on the Net may be of some use :
MACD Histogram Divergence
This explorer looks for stocks exhibiting extreme divergence from the MACD Histogram. In his book "Trading for a Living", Alexander Elder argues that divergence from the MACD Histogram gives the strongest signals in the whole of technical analysis.
ColA:
md := MACD();
mdhist := md - Mov(md,9,E);
Correl(((Sum(Cum(1)*( mdhist ),100))-(Sum(Cum(1),100)*
Sum(( mdhist ),100)/100))/((Sum(Power(Cum(1),2),100))-
(Power(Sum(Cum(1),100),2)/100)),((Sum(Cum(1)*C,100))-(Sum(Cum(1),100)*
Sum(C,100)/100))/((Sum(Power(Cum(1),2),100))-(Power(Sum(Cum(1),100),2)/100)
),12,0)
Filter Column:
colA and colA <-0.8
The above formula can also be combined with a volatility buy signal and a volume signal. The following addition is then made.
ColB: The volatility buy signal
H > Ref(C,-1) + 1.8 * Ref( ATR(10),-1)
ColC: Volume 10% above the average of the previous 10 days
V > 1.1 * Ref( Mov(V,10,E),-1)
Filter Column:
colA AND colB AND colC AND colA <-0.80
Initial tests with this system have been encouraging.