Most efficient way?

I’ve been working on a Isometric Tile Map editor. Currently I use a new movieClip for each tile, and when it gets like big, like 200X200 it starts to lag it, but I won’t be using something that large most of the time, so that doesn’t worry me. However, my tile sheet contains about 1040 tiles. And I want to create a scroll maybe 2-4 tiles wide that contains all the tiles, so when selected it would change the value of something and I can edit tiles… But I’ve been thinking and creating over 1040+ MovieClips might not be such a good idea (lol) would there be better way that I could possibly do this?