PBCS - Rule with variable in Calculation Manager

I have created this rule:

FIX (@Relative("SEVE_PARTIDAS", 0))

  DATACOPY "Actual"->"FY15" to "Forecast"->"FY16";

ENDFIX

With this rule, I copy in the account members (SEVE_PARTIDAS) the data, from Actual (Scenario member) of FY15 (Year member) to Forecast (Scenario member) of FY16 (Year member).

Now, I want to add a  {Percent} variable. Then, this value will use to calculate the amount. For example, the amount of "Forecast FY16" is the result of:  {Percent} variable  * (Amount "Actual FY15).

What instruction need to include in the rule above  with {Percent} variable?

Thanks a lot.