ax - How to find plan version by name

if ( this.RefType == WrkCtrCapRefType::PlannedOrder ) {
        
  reqPO = ReqPO::find( 
    ReqPlanVersion::findReqPlanId( "MAIN", "company", NoYes::Yes, false ).RecId,  
    this.refId, false );
        
  if ( reqPO ) return reqPO.ItemId;
}