Hmm, are you trying to map the left half of the texture to the back of the plane and the right half of the texture to the front of the plane like a playing card, like this maybe?
I wonder then do you want that part on the front or back of the plane and what part of the texture goes on the other side of the plane? Or are you trying to put that part of the texture on the back and leave the front like you have it?
EDIT: Sorry still having a hard time to understand but hopefully someone else will.