You can't really just convert a character directly from 3e to 4e. We pretended you could do that from 2e to 3e, but that conversion book was pretty well bogus. The fact is, as I explained it a lot at GenCon, that your character isn't what's on your character sheet: your character is the guy in your head. The character sheet is how the guy in your head interacts with the rules of the game. The rules of the game are different, so you'll be creating a new implementation of that character, but the character needn't change much.