Split a dual monitor?

I am using 2 computers. One with a single monitor, one with dual. The single monitor sits between the duals (The duals are large TVs on opposite sides of the space)

I would like to use Synergy to split the dual in half so that the mouse flows Dual-Left -> Single -> Dual-Right.

I tried:

section: screens
        single:
        dual: 
end 
section: links
         single:
                 right = dual(50,100)
                 left = dual(0,50)
         dual:
                 left = single(50,100)
                 right = single(0,100) 
end

I know this has issue, esp. the links dual part as it doesn't know how to leave/enter half way across the monitor space.

Am I asking too much of the program?

Thanks!