[Haskell-beginners] To use random number monad inside function

Hi: Haskell' s way of random number generation is strange to me, but I know how to do that. I' d like to know how can I call random numbers generated on the screen inside a classic function. I mean, I need to know the way of calling random numbers (one different every time that I run) inside a function. Please, Could anybody help me? Thanks