It is possible to add files to a visual studio project that is located in a different directory however keep the files in those directories and update those file when you update the file in the project? When I add existing files to a project, all it does is copy them to the project and then update the copied files, not the original files. Is there any way to get it to work the other way?
You should add them as a link/shortcut
Right-click the project, select Add > Existing Item, and in the dialog, "Add" drop down, select "Add As Link".