What is the ruling on someone who violates the law and marries behind the back of the first wife, and does the first wife have the right to legally complain against the husband, knowing that the law stipulates her consent before the judge?

The Sharia has permitted polygyny for great benefits, provided there is an ability to be just between the wives in terms of lodging and sustenance. It is not a condition for the permissibility of polygyny to inform the first wife or obtain her consent. What Allah has not made a condition, it is impermissible to make a condition, and there is no weight given to a law that contradicts the Sharia. The true believer abandons his personal desires for what Allah Almighty loves, for Allah, glory be to Him, is the Creator to whom belongs the command and judgment. If the husband strongly believes that polygyny might put him in legal difficulty or lead to the dispersal of his family, then it is more appropriate for him to abandon it until the opportune time and circumstances become available.