Solving for film coefficient h
 

Hello everybody,
I am aware this is like ANSYS101 (super easy) to everybody, but i am new to the software so any help and input would be highly appreciated.
I am a 2nd year mechanical engineering student, and i have just been assigned a heat transfer project, which is rather simple; however, my inexperience with ANSYS is proving to be exhausting. Let me elaborate a bit on my exercise:

I have a plate with fins connected to it and a natural convection of film coefficient h. As a brief overview of the boundary conditions:
1. The base is exposed to constant heat input of 130 W
2. The sides of the base are adiabatic
3. The sides and tops of the fins are exposed to convective heat transfer to surrounding atmosphere at 298 K.

Now the question is to find, using ANSYS software, the natural convention coefficient h in order to keep the base plate at 100*C. The problem with that is that in order to add the convective boundary condition, it is asking for the h value as input, which is supposed to be my output really.

Thank you for any help. :)