I would send him in straight into the blind (not around like a regular search), and have a long check line attached to something that will correct him (lets say a prong). As long as a hard correction on the prong won't shut him down...right before he gets to the helper and tries to get dirty...check him and make his position where you want it to be. You might have to check him farther from the helper and let him get closer the more you do this.
I posted a video close to what you are saying, he doesn't get a hard correction there but he does get checked. The prong just builds him, that is why the e-collar suggestion was made.