cell/vector operation to replace excel operation

I'm trying to convert simple math operations that can be done in excel into matlab language/script. Basically I'm trying to perform a moving average and need to loop N back into the equation while I calculate each N with the according date associated it. Where TR is the true range for that date. N1=sum(h4:h23)/20,N2=(19*N1 +TR2)/20,N3=(19*N2 +TR3)/20,N4=(19*N3 +TR4)/20.....where TR1=max(E4:G4), TR2=max(E5:G5)....N:end is basically a moving average of 20 days with formula of N=(19*previous N + TR)/20.

Answer 1

[Image Analyst]

Try movmean().