How to turn 1 pc into 2 in winnt

I have a pc installed with windows nt on it with a vga splitter by which I get display out put on 3 monitors. When I open multiple windows the same display I get on all the three monitors. What I want now is to get see one window opened on one monitor and the other on 2nd or 3rd monitor. It is possible in windows 98 with the help of a software “Betwin”. Can anybody tell me about such software for windows nt.