Its a move where you can scale a mountain. I don't know where to find it or what's it called. Please help! Btw, it's in Pokemon platinum!
Follow this link it gives a detailed description of how to get The HM Rock-climb.
Hope I helped :)
You know how to go to Snowpoint City from Mt. Coronet, right?
On the way, on Rt. 217, use find a house with an Item ball just North of it.
Grab that, and HM 08, Rock Climb is yours!