I just found a quick way to get a Pokemon to level 100. The only downfall to this is that some of the Pokemon wont know the exact moves you want, but it's still fun to use. Ok, here are the steps...
Region: Unspecified | Class: Individual Pokemon Codes
1. Enter in the code to make wild Pokemon be level 255 (01FFF3CF).
2. Go and catch the desired Pokemon, you can also use the code to catch any Pokemon (01XXD8CF, then look up the pokemon's number. Somebody else has probably posted it.) or steal from other trainers, (010168D0, I'm not too shure if it works the same way, but I'm 95% shure it does. Just switch the switch on and off again when you see the Pokemon you want to steal.)
3. Once you have the Pokemon at level 225 in your belt, get into a battle with it. (you'll notice that they're only good for one battle at that level.) so once the Pokemon recieves any exp. Then they'll level up to 100.(realy level down, but who cares.) and there you have it. 4. And again, they wont necissarily have the move you want, but you can use other codes for that I think.