You could update the crosshair position when a key event occurs:
Code:
import viz
viz.go()
court = viz.add('court.ive')
target = viz.addTexQuad(viz.SCREEN,texture=viz.add('crosshair.png'))
target.setPosition(0.5,0.5)
vizact.whilekeydown( viz.KEY_UP, target.setPosition, [0, vizact.elapsed(0.2),0], viz.REL_PARENT )
vizact.whilekeydown( viz.KEY_DOWN, target.setPosition, [0, vizact.elapsed(-0.2), 0], viz.REL_PARENT )
vizact.whilekeydown( viz.KEY_RIGHT, target.setPosition, [vizact.elapsed(0.2), 0, 0], viz.REL_PARENT )
vizact.whilekeydown( viz.KEY_LEFT, target.setPosition, [vizact.elapsed(-0.2), 0, 0], viz.REL_PARENT )