Well, I'm not an expert at Irrlicht but I know of at least two ways:
1) Use an animator, such as the "Fly Straight" one, and after creating it attach it to the animated scene node that has your mesh. With this you can specify the start and end point, exactly how far it travels.
2) You can use MeshSceneNode->setPosition() repeatedly in small increments along a path, although you would need to set those "steps" along with a timer if you want framerate-independent movement so the motion appears to be at a constant speed.
Both of these methods are detailed in the tutorials with the API, I'd start with the "movement" tutorial, which is number 4.
Yes.You got the point.
If I use , fly straight animator, it will take only straight line if my understanding correct.But I need the model to move in custom way rather than using any animator effects.I did not know whether this is possible the way you suggested using by timer and thought there would be better way to do this.That is why I just posted in the forum.Let me try this.