Physics Launching System but Semi-controlled

I am using Physics behavior for a sprite but it seems that I can't control the X independently as I was trying to make a launcher wichich launches vertically. With all the gravity and physics capabilities but I also like it so that I could control the X movement of the sprite while it's still ariborn. How do I do this?

object.physics.velocityX I believe....

No. I can't set velocity of X only. There should also be Y and since the Y should be affected by gravity not by the controls I can't use the Set Velocity.

oh crap..of course. now i feel dumb