Passing Variable Parameters to Inline Calls (customer_instantiation.cfg)

System

I am working on a custom instantiation screen for a workflow, which has a drop-down list to be populated by a custom data source.

I was hoping to do this using an inline call, but the data source needs the work area path:

<select delimiter="^">
  <inline command="Datasource:executeComponentopulateList:areaPath=work area" />
</select>

Is this possible? I would think the work area path would be known at the time this is executed. Am I wrong?