Got divorced from first wife now letting to meet child wants custody

I have two wives. My second marriage has been done with the consent of my first and second wife. And now 12 years later my first wife says that if you give a second wife a divorce, then I will let you meet your daughter. My daughter age is10 years i want her custody or visitation right, I have a boy from another wife. I can not survive without my daughter. It's been a month since I did not meet my daughter. My daughter can not live without me. My daughter's mother is my first wife. She is a government servant. She has been living with another room for me since one month. In this, her mother encouraged her against me. my first wife is my daughter's mother is suffering from a sexually transmitted decease form last few years ago .And her health is not good enough.