To add HLP files to your application, you’ll need to package the help file with your project and then call it from your code using the correct system functions. Since HLP is an old Windows help format, make sure the target system supports WinHelp. Place the .hlp file in your app directory, then trigger it with a call like WinHelp() or ShellExecute(), depending on your framework. If you’re targeting modern Windows versions, you may also need to install the WinHlp32 update from Microsoft because it’s no longer included by default.