I need a slightly tweaked Reflection Vector

Is there a way to create a simple version of the reflection vector in a material, that uses the camera’s world position rather than it’s rotation?

Effectively what I’m trying to do is map a texture across a surface almost as if it’s a camera-facing sprite. Using reflection vector works when I look dead-straight at the center of the object, but if I rotate the camera to face away, I start to get banding and stretching. This is probably quite simple, anybody know vaguely how to set it up?

Here’s how I’ve done the view-aligned texture, but I need to replace that reflection vector input with my new position based math instead. The circle on the right is actually a circle texture, but no matter how I rotate the sphere or the viewport it stays in a circle shape relative to the camera.