Environment Variables plugin
Environment variables editor plugin allows setting environment variables in the focus of Code::Blocks. A user can have several sets that contain 1..n environment variables. A user can switch between these sets within the environment variables configuration dialog. In addition the envvars plugin offers an option to projects (within project setup) to apply a certain envvar set to activate (and use during compilation).
The dialog for editing the sets is located in Settings->Environment->Environment variables.
The dialog for choosing the active set for the current project is located in Project->Properties->EnvVar options.