How can I control nxt 2.0 robot with a Wiimote in labview?
The Wiimote uses 2 forms of communication: Bluetooth 4, and IR for the pointing controls. You'd probably be using bluetooth.

The main problem with the NXT bluetooth is that the NXT is a slave device, not a master device, while the wiimote itself is a slave device as well. For advanced reading on the interfacing methods, the wiibrew community has set up a great page over here: http://wiibrew.org/wiki/Wiimote

The next concern is that you may have to modify your wiimote a tiny bit for bluetooth data transmission. right now, most of the homebrewers are hard-shorting wires to trigger events.

As far as files for the NXT, I'm afraid that you will likely find little to no files, as the problems stated above are somewhat above what most NXT users are trying to do. 

Best of luck on your project!