ActionScript 3.0 :: Randomizing Symbol Movement Within Range

Basically, I've got a small space shooter game and the idea is to have the enemies start moving at the top of the screen and head towards the player, while growing in scale, and moving at an angle.(To give the sort of perspective/distance effect). Right now, I'm able to get the enemies to move at one angle only. How would I get them to move on X at a certain range?

This is the code affecting movement/Scale
for( i = 0; i < enemyShip.length; i++ ){
enemyShip[i].y += 10;
enemyShip[i].x += 5;
enemyShip[i].scaleX += 0.03;
enemyShip[i].scaleY += 0.03;
}
The pic above basically shows what I mean by the perspective look. I need to blocks to move towards the player at various X ranges within those lines, but I don't want them to zigzag while moving. I know it has to do with Math.Random.