I would like to create a Build Definition inside TFS 2012 Express which will simply copy all files within my project source tree to another folder on my drive. Just to underline
Using this post as a guide on how to start editing TFS Build Templates (or the Wrox TFS 2012 book), you need to make the following changes:
Path.Combine(BuildDetail.DropLocation, "MyOutputFolder")
Path.Combine(SourcesDirectory, "MyFileFolder")
You may need to repeat this if you don't have all your files in one folder.