Warp StandardSpecular Reflections WITHOUT Affecting Viewdir?

Using the StandardSpecular surface model, how can I warp the final reflections without affecting Viewdir input? I'm using rim effects, and so adjusting the material's o.Normal directly affects the rim as well, usually leaving me with a plain rim-colored material. Is there a way to access the reflection-probe-generated-cubemap's UVs (like in the built-in Bumped Distort glass effect)?

Any help is appreciated, and please forgive any painful mistakes or oversights on my part, I'm still in the early stages of learning shader syntax.