how do you trim a composition in half and export it that way?

[EltonJohnisPlumpandDreamy]

I'm working with two projectors and it's important that my movie is divided exactly in two, because they are supposed to look cohesive--as if the two projections made up a single image.  My question is, how can I split the composition (1920x1080) perfectly in two and export the two separate vids?

[Roei Tzoref · Accepted solution]

1. right click on the master composition in the project panel and select "new comp from selection". call it "Part 1"
2. duplicate "Part 1", it will call it automatically "Part 2"
3. click twice on "Part 1". go to "Composition Settings" (Ctrl+K on Win). go to "Advanced" and press the right arrow on the anchor. now go to "Basic" and divide 1920/2. click OK
4. click twice on "Part 2" and do the same as 3 just change the anchor to the left arrow before you do.