BPMN - how to convert an embedded sub-process to a callable Global Task?

[Paolo F Cantoni]

I have a BPMN process to which I am applying simulation (BPMN only, not BPSim at this stage). The process calls some embedded tasks (i.e. Tasks with their own BPMN Diagram) in the same folder as the top-level BPMN diagram.  The simulation proceeds, and the called tasks are entered and executed in the Simulation Window as expected.

I would have thought it should be fairly easy to convert such an embedded task to a global callable task called from a number of higher-level BPMN diagrams.  But for the life of me, I can't seem to get it to work!  I would have thought this would be a common scenario and there would be Help documentation to help me, but I couldn't find it.

Is this doable?

If it is, I can set up the higher-level tasks with simulation parameters that would be passed to the global task and allow me to simulate a number of scenarios against the same process.

TIA,
Paolo

[Edit: if you search the forum, you'll find I can manage the process once I get the callable Global Task or Callable Business Process.  However, I didn't document how to connect up the global item, so I have a "Catch-22"]