Maybe this will work
 

Not sure if this will work for you, but this is the best I could do for my setup.
Change your center monitor to a resolution of 1440X900
Change your 2 outer monitors to a resolution of 1152X864
Change your conf.ini to

[window]
width=3744
height=936
ColourBits=32
DepthBits=24
StencilBits=8
ChangeScreenRes=0
FullScreen=1
DrawIfNotFocused=0
EnableResize=0
EnableClose=1
SaveAspect=1
Use3Renders=1

[GLPROVIDER]
GL=Opengl32.dll

[GLPROVIDERS]
Open GL=Opengl32.dll
DirectX=dx8Wrap.dl

Hi Sita
 

Thank you very much, now is working fine with your configuration.
But tell me, Do you know how the other guy managed to use 5760x1080? because that is the resolution I currently have, but I cannot make it work in IL-2.

No sorry