Child custody battle...

I am a Wisconsin resident and am in need of advice. I am in a child custody battle with my ex-wife. The court has appointed a guardian adliteum to the children. Recently I recieved a subpoena in the mail from the guardian adliteum, of which I was to report to my ex-wifes attorneys' office to give evidence in this matter. The guardian adliteum asked several questions of me under oath, while my ex-wife and her attorney were present in the room. After he was done, my ex-wifes attorney asked me several more questions.

My question of you....

I believe the guardian adliteum has been prejudice against me as he has not listened to any of my concerns in this matter and has befriended my ex-wife and her attorney. Is there a statute against such behavior, and if so what and how would I go about communicating this to the judge to possibly have him removed from the case?

The subpoena also was written by the guardian adliteum, my ex-wife and her attorney were not listed on the subpoena. Should they have been allowed in the room while being questioned? Should they have been allowed to ask me questions under oath? Have any statutes been broken or any wrong doing been done by these parties? If so what and how can I go about reporting it? Can I ask that any evidence gained by my ex-wife or her attorney be stricken from the record and inadmissible in court?

Thank you for your time.

carrie&bill