Pokemon platinum how to move the guy blocking Mt- cornet?

You don't need to move the guy blocking Mt. Cornet in Pokemon Platinum. He's actually the Pokémon Ranger, and he's not blocking anything.

Here's how to get past him:

1. Talk to the Ranger: He will introduce himself and then let you pass.

2. Continue to Mt. Cornet: You'll need to use the "Strength" HM to move the boulders blocking the path to the mountain.

The Ranger is there to help you and doesn't actually prevent you from entering Mt. Cornet. He is simply part of the story and is there to provide some context.