Multiple monitors hackintosh setup question

Hi i am running a hackintosh with leopard 10.5.8 with good success.

My specs are

Asus P5k - premium wifi
intel q6600
ram 6 giga 1066
2 video cards 1x Evga 512 8800gt and 1x msi 1g 9400gt
2 sata2 hds
1 sata2 Lg dvd recorder.
4 lcd monitors

I am trying to have the 3 monitors at my main room and one more mirrored with my main display to an other room.

So i have connect my main monitor and this that i want to mirror to 8800gt
and the other two monitors to 9400gt. I am trying to find where i can do this to monitor preferences but i can only mirror all the monitors or extend them all.

I search to google for a solution but i can't find any answer.

thanks for the help