Metal above windshield repair help

[Rednek13x]

My main goal is to get my cab to stop leaking when it rains. And to seal it off as best i can.. My biggest problem is on the inside above the windshield, as you can see in the picture it is pretty rusted out, although it does not leak there i would like to patch this up.

I would like to know how others have done this, what the best way to do this is. My truck is not a show truck, i am just repairing it to make everything solid again. I need help on this one.