[Haskell-beginners] Random computation with fixed seed value (Control.Monad.Random)

Hi, I'd like to evaluate a random computation using Control.Monad.Random, but I'd like to be able to fix the seed value. I know I can use mkStdGen from System.Random to get an initial generator. I also know I can use evalRand :: RandomGen g => Rand g a -> g -> a from Control.Monad.Random to evaluate a random computation. But the problem is I don't see how I can turn a StdGen value that I get from mkStdGen into a Rand type. What am I missing here? Best, Jan