Let me rephrase what I think you are saying. You are moving left (for a righty) and having a hard time walking diagonally to your release point/target? (As you want to walk straight).

Move your target down the lane.   The drill of looking your target line to your target is helpfull.   It's really more of fooling your eyes and mind to not throw at the pins.   Practise!!!!!

Just what CharlesT suggested - try to concentrate on execution and focus un your target, ignore the idea that you play in an angle across the boards. I had big trouble for a long time converting 4s and 7s with a spare ball, because I had to play straight across the lane, and was frequently confused by the angled boards in my vision field. It distracted me a lot. I overcame this through staying square with shoulders and hip to my target, just focusiing the point on the lane across which I intended to play the ball straight. I'd project a line from the target pin through the target and my straight pendulum swing plane, and turn my body accordingly - keeping anything else as usual, with the idea in my mind that I actually CAN project a ball straight down in autopilot, and that this "full body aiming" should suffice. And it actually does! I just focus on the target and a good follow-through now, and this works like a charm. Another good point is that I can apply this technique almost blindly, and it works basically also for strike shots. Instead of steering the ball I just focus on the target and proper execution. The ball reaction down the lane comes more or less automatically, so that I can blend out even deep angles. I just need confidence im my release and the ball's reaction.

DizzyFugu - Reporting from Germany
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Its trial and error my friend, there a many ways to accomplish this you just have to figure out what works for you. A good starting point is like someone else mentioned, get a feel for looking further down lane-think where you want the ball to be at the end of the pattern.

 

Another point is to get used to opening your shoulders and hips a little more in your stance. This can seem very weird at first for someone who is a straighter player and is used to staying more square throughout their approach. Take some time to work on presetting the angle of your hips and shoulders in your stance. Start out around 15 at the arrows, and play around with different stances. One thing I do is I stagger my slide foot in relation to my right leg because Im right handed. Generally, the deeper I play the more stagger, or further away I place my slide foot in my stance compared to my right leg. As you get more comfortable target different arrows, and project the ball through the arrows and to your breakpoint. As you move deeper, turn your hips and shoulders to different angles towards the right gutter if you are right handed, untill you can hit your target consistently. Dont be surprised if the deeper you move in, the closer to the foul line you have to look to get the ball to read.

 

Another thing I have done is turn my feet to the right just a hair, so that they are facing towards my breakpoint, or where I want the ball to be at the back of the pattern. This is especially helpful on those conditions later in tournaments where the front part of the lane is fried and I have a breakpoint towards the gutter I need to hit.

 

The key is to practice it, find what works for you. Also, Ron Clifton at www.bowl4fun.com has some great articles for this subject, and he is a great coach who I have had the pleasure to work with a time or two. Good Luck!!