How to form "employee welfare trust"?

To all professionals.

One of the assessee company wants to form a trust for providing medical incentivesto its employees and Sec 40(a)(iv) reads as under :

" any payment to a provident or other fund established for the benefit of employees of the assessee, unless the assessee has made effective arrangements to secure that tax shall be deducted at source from any payments made from the fund which are chargeable to tax under the head “Salaries”"

My query is regarding how to form this trust?