First, on what basis are you suggesting that DCCS is violating the "civil" code by its actions?
Which civil code are you referring to, and, which provisions of that code do you think are being violated? Keep in mind that the CA Code provisions that you cited previously are part of the CA "civil code", and, that they seem on a quick read to authorize the levy. If you want to argue that the levy violates the CA "civil code", you will have to explain away these provisions, and, find some that support your argument.
Second, with regard to the argument that DCCS is violating the "revenue code", do you have any basis for this argument? The term "revenue code" is probably most often used as a synonym for the US Tax Code, and, I am not sure by any means that the Tax Code has any provision in its volumes and volumes of regulations that "prohibit" the attachment of an IRA for the payment of child support. The Tax Code is designed to address what is and what isn't taxable and to define the regulatory scheme with regard to federal taxation -- and so, while it may state that an IRA contribution is tax deductible up to a certain dollar amount, it does not regulate whether or not an IRA can be attached for child support.
This may not be the answer you want to hear and I urge you to discuss the matter with a knowledgeable CA attorney, however, I cannot envision any scenario wherein the lawsuit you are contemplating has any chance of succeeding.
Finally, a common sense argument: Remember that an IRA is funded by the contribution of one's already-taxed earnings -- or, in other words, it is funded by the contribution of portions of one's paychecks or of one's earnings that are received in some other form. Given this fact, if the DCCS can levy your paychecks, why can't it levy portions of your paychecks that have been deposited in an IRA?
I hope this was helpful to you. If it was please remember to click "ACCEPT" on your screen to make sure that I am paid for my efforts. By clicking ACCEPT you are not giving up your right to ask more questions on this issue, and I will be happy to respond to these as well.