To add an existing file to a PL/I project

  1. In Solution Explorer, right-click the project, and click Add > Existing Item.
  2. Set the file type filter to the desired file type.
  3. Browse to the location of the file you want to add, select the file, and click Add or Add As Link.

    This adds the file to the project directly or as a link, and opens it in the editor.