How to push planner order demand to a plan as FCST

Hi All,

Could you please help on below request.

We have multiple plans. in which Plan#1 creates Planner order demand and this planner order will create WO. Where as these items are manufactured in another organization and it is not part of this plan.

We are planning to collect these planned orders and make as FCST to the Plan#2 (where these items are finished goods moslty make items in that org.

We have taken those planned orders and placed into msc_st_demands and msc_st_designator. Do we need to create a forecast_set or simple designator will work.