For that first bit, it works as follows:

gotoAndPlay(scene,frame);

You would place that within a button event or on a frame panel.

I don't understand exactly what you mean by "zoom in a movie clip when it is playing", but I'd assume you mean that you want to zoom into the canvas as the animation is playing.

For that, A V-CAM would suffice. The "V" stands for virtual, it acts as a camera on the canvas that can be resized to zoom in and out and rotated.
Hyun's V-CAM

Hyun has a link in the description that allows you to download V-CAM for AS2, which I assume you have.

Good Luck.