http://isboxer.com/wiki/Multiple_game_folders

To check an existing Game Profile:
1. Right click Inner Space in the system notification area and select Configuration
2. In the configuration window, select the Game Configuration tab
3. In the first drop-down box, select the Game
4. In the second drop-down box, select the Game Profile

The "Main executable path" is what you are looking for. The parameters box is where you can put -d3d9 or -d3d11 to have WoW use Direct3D 9 or Direct3D 11.