a:=12;b:=26;x:=2/(1+a);y:=2/(1+b);
top:=Mov(C,b,E)*(1-y)-Mov(C,a,E)*(1-x);

{C required for trigger line crossover}
(Mov(MACD(),9,E)+top)/(x-y);

{C required for 0 value MACD}
top/(x-y)