§ 21-a. Company pension plans; deductions from wages trust moneys; preference. Moneys contributed from wages or salary by an employee or former employee under any retirement system or plan maintained or operated by a domestic corporation, association, co-partnership or joint-stock company, together with all accumulations of interest, shall belong to the employee making the contributions and be deemed to be held in trust by the employer for the benefit of the employee. In all distribution of assets of such an employer or former employer, whether insolvent or otherwise, the amount so contributed, together with such accumulations of interest, shall first be paid to the employee or former employee, his executors, administrators or assigns, before payment of unsecured creditors.