Is your husband's company hiring? Would love for my hubby to find a job that creates a "need" for us to go to Disney World. I did a little checking for you and found out that typically reservations made thru a company as part of a convention package is not eligible for ticket and dining packages. There are a couple exceptions though.
One would be if your husband's company has set up an option thru Disney's travel company to include package options for the employees that may be traveling with their families. Your husband would need to ask his employer or travel agent that is handling this trip.
The second exception would be the decision of the Disney resort you are staying at. You would need to obtain your room reservation number that was booked for the convention, then contact that Disney hotel directly and ask them if they would be able to specialize your husband's reservation to include a pass and dining package. I have been told by Disney's travel compnay that this may depend on the room rates, occupancy and a number of other factors.
One thing to consider is typically any Disney package booked must be purchased for all occupants of the same room. This means that your husband would need to book the same package that you and your children are requesting. If he has free time this may be a great option, but if he will have no time for the parks and will not be dining with the family then this extra package may end up costing more than you would save on the package. Again you can discuss this with the individual resort and they may be willing to make allowances but there is no guarantee.
If you are unable to or decide to not book a package, you may want to check
www.mousesavers.com for savings on park admission. If you are AAA members, be sure to call and ask them about any discounts they may be offering for park tickets and dining options.
Hope you have a magical trip!