MetaStock -> Tools -> Indicator Builder -> New
Copy and paste formula below.

===========================
Harmonic Pattern Correlator
===========================
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{ Stock/Harmonic Pattern correlator v1.0 }
{ Plot on own window below price chart }
{ Zoom out & cycle trough stocks }
{ Search for meaningful patterns }
{ ©Copyrite 2004 Jose Silva }
{ http://www.metastocktools.com }

xshift:=Input("x wave shift (0~100)%",
 0,100,50)/100+1;
yshift:=Input("y wave shift (0~100)%",
 0,100,33.333333)/100+1;
zshift:=Input("z wave shift (0~100)%",
 0,100,20)/100+1;
scalar:=Input("Scalar (1-100)",1,100,33.333333);

x:=Sin(Power(Cum(1/H),xshift));
y:=Sin(Power(Cum(1/L),yshift));
z:=Cos(Power(Cum(1/C),zshift));
odd:=Cum(1)/2=Int(Cum(1)/2);
pattern:=If(odd,x+y-z,x-y+z)*scalar;

pattern

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