How to add a substitution variable with mass edit to allocation rules

Summary:

I use the same allocation rules for actual and planning (2 different models), but planning allocation shall still be based on actuals hence I want to change the driver scenario and year from "Same as destination" to "Actual" and "&ACT_YEAR".

While "Actual" can be added with mass edit "Add Member"

it is not working for the substitution variable.

mass edit "Replace Member" also cannot be used because the current status is "Same as destination". Hence, no specific member can be selected in the find member field but empty field is also not allowed.

My question: How can substitution variable easily added to a lot of allocation rules (as a driver)?