After making my previous post, I nosed around in Google and found what purports to be Constance Brown's Composite Index on Forex Factory and some other sites (coded for use in MetaStock):
CI = rsi(14) - ref(rsi(14),-9) + mov(rsi(3),3,s);
plot1 = mov(a,13,s);
plot2 = mov(a,33,s);
a;plot1;plot2...