You are probably using an Effect: those are here to make quick and easy animations but you don't have control over details of the animation.
For what you need, maybe you can instead mark the object as "hidden" in the properties inspector and place it on stage on the "starting" position. Then add a "show object" and a "move object" actions (sticked together so they execute at the same time) in the "Load" event of the object to show and move the object the way you want.