Have a look at this post from Ewald Hofman, it updates certain files and checks them in using a custom activity. You could use the same process. But this involves customizing the build process template and deploying custom build activities to all build agents.
But you might also want to investigate the free AIT Dependency Manager which can download the latest specific version (can filter on build outcome or quality) of one build from the buildserver as reference to another build (also inside Visual Studio). This is a lot more flexible than constantly checking in the build output and allows you to have your dev branch to always get the latest (unstable) version, but your release branch to always get the latest well tested and approved version.