external monitor via ethernet cable, how do i tell apple 2nd monitor?

I'm running 10.6.8 on a macbook pro

i am operating a video switcher for football games. I need to use the macbook pro as an input for the video switcher, and the only way to add it is via Ethernet cable (because the switcher does not have VGA or other inputs for it). The switcher came with a program called iVGA, which, when installed, can connect with the switcher and display one computers screen onto the switcher via an ethernet cable or if both comptuers are connected to the same internet network.

THAT part you kinda need to know so you don't tell me to connect another way, cause this is the only way i can.

My question is, when i'm connected with this ethernet cable, it mirrors the computer screen onto my swithcer, but what i need it to do, is to display a second monitor screen from the computer. Normally I can go to Preferences, Displays, and there is a button called Arrangement that shows both the main monitor and the second monitor. but it's not showing up since i'm not connecting a displayport to the computer, only an ethernet cable.

is there any way into forcing the computer to create a second display monitor even though all i have connected is an ethernet cable?