divorced father wants to apply for a dependent visa for my daughter

Hello
I hope if you could help in my case
I'm a doctor and preparing to move to the UK on tier 2 visa
I'm a divorced father and my 2 years old daughter lives with me at the moment at Egypt. Simply my ex-wife gave her to me.
Officially, I do not have the custody for the child and its nearly impossible to obtain the custody.
what documents should I prepare to prove the sole responsibility?

Thank you

You need official documentation.

Sole Responsibility Requirements (click to read)