Yeah, you can do that with setplayerdata.
setplayerdata prestige 4 (0 = no prestige, 1-20 => Prestige levels)
setplayerdata experience 420 => 420 XP (you need to either google the XP, try it or calculate it)
setplayerdata is a rather mighty command so don't play too much around with it if you are not ok with resetting everything.
thanks a lot!