Hello
You mean, you're husband is back in your home country now? Is he the principal applicant? For sure, that company has an email address or contact number. Your husband may write a letter through email requesting the duties and responsibilities of his job. Or he may call them. If they will provide him, ask them to send it by courier to meet the deadline of MPNP. Just offer the company the payment for the courier service. You may also ask them to fax it which is faster.
Early as now, make a letter to MPNP, stating that you are making steps to comply with their requirement but you are not sure if you can provide it before the deadline. It is important that MPNP knows that you are working on it, I believe they are considerate enough to give you extension.
I think, work visa is not really what they need, since you already submitted the COE. What they want is to assess the job of your husband by knowing his duties and responsibilities. You may do submit the scanned work visa along with the letter, anyway, it will not do any harm.
Let's wait for other members opinion so that you can decide on what's the best thing to do.