From within the IDE, you can create new environment variables to use with the building of your applications. Use the Build Environment properties page, in either the project settings or the build configuration settings, to create a variable for use throughout a project. Building the project adds the information about the variables to the application.
To use these variables at run time, you can configure the run or debug configuration to inherit them, by selecting the Inherit values from the build environment of the associated project option, available on the Environment tab. From here, you can also add further variables. Any variables set here that duplicate those that are inherited will override the inherited values.