SMS receipt confirmation, proof it was read, confirmation code

We are a construction company and when we send a SMS to our employees notifying them of a job, we would like for the SMS sent to receive either a confirmation/proof that it has been sent and read or better still for them to have to reply back with a unique 4 digit code. Many of us have that with our Dentist and our Mecanic here in Quebec, Canada, and we feel it’s a must have tool with SMS.