[Lucky13]

Вот так:

static void joinFile(TableId tableId, RecId recId, DataAreaId id, DocuTypeId typeId)
{
    docuAction    action;
    DocuRef       docuRef;
    ;

    docuRef.ValueRecId = 0;
    docuRef.RefCompanyId = id;
    docuRef.RefTableId = tableId;
    docuRef.RefRecId = recId;
    docuRef.TypeId   = typeId;
    docuRef.insert();

    action = DocuAction::newDocuRef(DocuRef);
    action.unpack();

    action.add(docuRef);
}