There is no C+ language. As for Ladder Logic in C++ or VB, don't know but it looks like you will probably be better off converting instead of trying to intermix things.
I worked with machines years ago that used Allen Bradley PLCs, and the guys who set up the units worked in Ladder Logic. I was always sort of curious about it, but when I looked at the code it was like nothing I'd ever seen. I'm curious as to what aspects of it you would replicate in a procedural C-like language. If there's a mapping that makes sense then I wouldn't be surprised if it's already been done.