Recording the centre screen only.

[Nemesis]

I am new to using Action and I was wondering if there is an easy way to game capture just the centre screen of my 3 monitor setup?
I run in a resolution of 5760 x 1080 but I would like to only capture the middle 1920 x 1080.
Using the area capture mode seems overly fiddly and inaccurate.
Any advice would be most appreciated.

[radi]

Are these displays extended?

[Nemesis]

Yes my desktop is extended to all three displays.
But this is exclusively for recording game footage.