You could create another file with the version number in the java property (key=value) format. Then you can use the EnvInject plugin to inject the environment variable (MY_NEW_VAR) into your job/build. The advantage of this approach is that the variable can be visible throughout the whole job/build. You just enter the path/myVersion.txt in the Properties File field of the plugin.
Alternatively just use DOS, eg: To place the first line of a file into a variable, do this Set /P MyVar=<aFilename> The downside to this later approach is that you may have to repeat it if you open several shells.
