What is the Islamic ruling regarding a Muslim working as a lawyer and a judge guided by secular (man-made) law even in a Muslim country?

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Working as a lawyer is permissible in itself as it is but a mandate to defend the rights of a client or seek the rights for another one provided that the lawyer avoids lies and untrue facts and defends the truth only.
So, the lawyer should study the legal case from all sides; if he finds that the truth is with his client or mandator, he should stand with him and defend him: If the opposite is true, he should always stand with truth and in this case, he should clarify it to his client and advise the latter to give up the rights to their true owners. All this is permissible only if the court is an Islamic court that uses evidences from the Qur'an and the Sunnah. But if the client chooses to put his case in the hands of a court that uses secular law while there is an Islamic court in the area, the lawyer in this case should not defend this client. On the other hand, if there is no Islamic court in the area and the client had no choice but to put his case before this court, it is then lawful to the lawyer to defend this client under four conditions.
First, the lawyer should study the case and know beforehand whether the lawsuit itself and its proceedings conform to Sharia, if that is not the case he should not defend it. Second, it is not lawful for him to defend his client in a case which is void and false. Third, he should not seek to get some rights on behalf of his client that are not his. Finally, he should clarify the right and say only the truth.
As for working as a judge in the secular courts, one should avoid that because being bound by secular rules he may make a false decision that could cause him to lose his religion.
Allah Says (interpretation of meaning): {So, judge among them by what Allah has revealed, and follow not their vain desires,}[5:48]. And Allah also says: {Do they then seek the judgement of (the days of) Ignorance? And who is better in judgement than Allah for a people who have firm Faith.}[5:50].
In most cases, the judge in these courts is bound to apply the secular law and is not permitted to use Sharia. If this is true, it is unlawful to work as a judge in these courts. But, if the judge binds himself to the truth and makes only decisions that are right and if he does not make any false judgement, and if he applies Sharia rulings on the issues he deals with, and if he denies applying secular law if it is in contradiction with Islam; if all these conditions are met, his work in such courts is permitted.
Allah knows best.