Custom sky dome

Is it possible to setup a custom skydome and have meshes move through it on a loop to give the appearance that the map is moving. Like if the map was set on the back of a jet flying through the desert. I did this in several maps for 2k4 but cant figure out this new editor or the blueprints. I found an old video of my maps so you can see. The jet and tanks are just large meshes and the mountains and trees are flat meshes traveling through the skydome, not the map. Same for the fireworks on the russian snow map. They are particles inside the skydome, not the map.