How can I reverse the reflection vector used by cubemaps?

Hello, I am currently trying to wrap my head around reversing the direction on the Z axis that one material will reflect with, so instead of reflecting what is infront of it, it reflects what is behind it. Something like setting the “source cubemap angle” to 180 in reflection captures, but using the image captured from the reflection capture and only in one material. I’ve tried messing around with normals and backfaces but can’t seem to figure it out. Can anyone push me in the right direction?