Task manager - possibility to use variables as Parameters in tasks?

Summary

Task manager – Connection to ARCS – Task type: Monitor Reconciliation. Possibly to use variable as Parameters?

Content

When connecting a Task manager task to ARCS using the Task type "Monitor Reconciliation", is there any way to use a variable as the Period Name parameter? 

Otherwise we need to change the Period name manually every month. (Extract to excel, find/replace, load). We do not want to have a manually process where we need to extract all tasks to change this as it is time-consuming and a risk for mistakes. 

 

I have tried to create a Variable under Task manager / Tools / Variables / Substitution Variables. But it did not show when creating a task so I assume this was the wrong way to do it