Referring to following linked articles, I would like to code investment's rate of change in Metastock,

Does anyone have any suggestions on how to code it?

Thanks in advance for any suggestions :>

There is more than one way to calculate an investment's relative strength. One method is to rank all investments within the same investment universe and purchase the top performers. Another is to take the six-month rate of change in an investment's price and divide it by the six-month rate of change in a relevant index. The investment's rate of change is divided by the benchmark's rate of change to get a relative strength value. If the value is greater than one, the investment is relatively strong; if the value is less than one, the investment is relatively weak.

http://www.investopedia.com/terms/r/relativestrength.asp