The design pattern you are looking for is the adapter pattern (wikipedia).
The adapter pattern (often referred to as the wrapper pattern or simply a wrapper) is a design pattern that translates one interface for a class into a compatible interface...
One way to implement the adapter pattern is to create a generic interface (abstract) for the vector class, and then you could derive classes from it that call the correct functions.
To switch between the concrete derived classes you could use a typedef. e.g. you would define
typedef VectorDirectX Vector
or
typedef VectorOpenGL Vector
and then you would only use Vector in your code. This would only work if you weren't planning on switching Vector classes at runtime.
If you did need to switch between them at runtime you could use a factory, which would create the required class and return a pointer/reference to the base abstract class.
In practice though,In practice for performance reasons I'd rather rely on refactoring tools (e.g. Visual Assist) to rename functions and classes unless I'm working on a massive project or there's a legitimate reason why the classes would need to frequently change.