Alternative Key in Model

I am just fighting with a problem on relations in Models.
I have moved from the conventions changing the primary key.
$this->hasMany(‘Costcenters’, [ ‘foreignKey’ => ‘account_no’, ]);

That works fine. The purpose is I have to avoid lots of new entries each new year. OK so far so good, but I need an additional relationship like:

   $this->hasMany('Journals', [ 'foreignKey' => 'actAccount', ]);

which is containing the id of the related account.
Can I have both? I read the cookbook/Table Objects several times but have not found the way.
Thanks in advance

you can add as many associations to your table as you like

        $this->belongsTo('Projects', [
            'foreignKey' => 'project_id',
            'joinType' => 'INNER',
        $this->belongsTo('EasybillDocuments', [
            'foreignKey' => 'easybill_document_id',
            'joinType' => 'INNER',
        $this->belongsTo('ProjectDocumentTypes', [
            'foreignKey' => 'project_document_type_id',
            'joinType' => 'INNER',

just put them underneath each other