Under what circumstance is a Muslim sister or sisters allowed to take legal action in a non-Islamic court, against an Islamic association with the claim of sexual discrimination? For example, does Islam under any circumstance allow claim to financial reward for stress caused by a Muslim brother toward a Muslim sister. (i.e. discrimination - sister not allowed to be a voting member of the association which has the authority to select an Imam) At this point the majority of the community would like to keep this away from the media; however this may not be possible based on the underlying motives behind this whole issue. So basically, I as a Muslim would like to know under what circumstance one Muslim can take another to a non-Islamic court claiming damages (financial) from an Islamic committee. I.e. Is it mandatory for the group taking action to request mediation from three to five recognized Imams, between the two conflicting groups, prior to taking action in the non-Islamic legal system?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Muslims are required to solve their problems among themselves, without allowing others to interfere in their affairs. Also it is not permissible for them to present their cases in courts of positive laws that do not recognize the difference between the right and wrong. In this vein, Allah (The Great and Almighty), while describing those who sue one another in such ways, Says: {Have you seen those (hyprocrites) who claim that they believe in that which has been sent down to you, and that which was sent down before you, and they wish to go for judgment (in their disputes) to the Tâghût (false judges, etc.) while they have been ordered to reject them. But Shaitân (Satan) wishes to lead them far astray.} [4:60].
So, since it is decided that believers have to remain loyal only to their believing brothers, it is Haram to demonstrate any form of loyalty to disbelievers or to follow their opinions. It is known and clear that it is also Haram to present any case in courts of positive laws as long as there is some Islamic circle/body that can settle a dispute. In addition, the mentioned issue does not necessitate a financial compensation, since it does not constitute a form of encroachment on property nor fiscal loss or felony against somebody or anything else.
Then, the utmost degree of this issue is just denying a woman to vote to select an Imam. If it is supposed that the woman has the right to vote on selecting the Imam, such an issue has no fiscal value that necessitates compensation.
Allah knows best.