Agree with the employer that the wages were paid partly officially, partly "on hand". Then child support will be deducted only from the official wage. Not every employer will take such a step, it is threatened with severe punishment.
There is such a thing as "indefinite leave without pay". This happens when the organization is unable temporarily to provide work to its employees, but to save valuable staff sends in a vacation that will last an indefinite amount of time. You can discuss this issue with the employer and receive your payment in the envelope, but the years in this vacation to hold you, no one will.
You may have property and can give the property to the child. Coordinating the matter with the child, it is possible to conclude a contract on transfer of property in exchange for the suspension of alimony payments. Take a calculator, calculate approximately how much alimony you have to pay, subtract from it the value of the property.
It is possible to sue to reduce the amount of alimony if you can prove that the money is spent by the mother for other purposes. To contribute partly to the personal Bank account of the child, which he can use upon reaching adulthood. You need to write an application to the guardianship, and they are required to verify use of the incoming alimony.
The court