I just can't think of how this will work. So if you would be so kind as to assist me, I was wondering how you would change the controls to this:

North: Go in the direction the player is facing.
East: Turn player to there right 90 degrees.
South: Player walks backward.
West: Turn player to there left 90 degrees.

So if im facing west and i press up then i continue to go west. if im facing east and i press right then i will face south. if im facing south and i press left the i will face East. etc. etc. Thanks for yor time and effort, cause I can't think of anyway to do this.