afl- codehelp

Please help to write this code:
BUY : When price of last 4 months is 3 yrs high

Thanks,
DHAVAL

Assume:

5 trading days per week
20 trading days per month
52 trading weeks per year is 260 days, Use 260 or take away your own
country holidays. assume 10 holidays per year = 250

4 Months = 4*20;
3 Years = 3*250 OR 3*260;

Buy = HHV(C, 4*20) > Ref( HHV(H, 3*250), -1);