Teaching AE is not something we can do in a single thread. The learning curve is quite literally months. I mentioned AE because I've noted that in Adobe Production Studio that Encore and AE are more closely linked (due to the menu options available) than Encore and Premiere are.
By far your best bet is to save your Encore menu as a layered Photoshop file (which is what it already is

) then import that as a sequence into a Premiere project. Bring in your orginal clip/image and animate/keyframe a zoom transition. Export that as an AVI and use that as your Encore transition.
There is not automation of such things that can be done in Encore. Every little bit of animation needs to be built beforehand. All Enciore is capable of doing is playing a pre defined clip between 'events'. It's up to you to build that clip. Needless to say, the real art is making it look like a seamless piece of animation.