Add a thread process to an existing Delphi 64bit project

We have an existing delphi 64bit project that creates a DLL to perform certain tasks. We need an additional entry point in the DLL that will take a string as parameter, pass it to a running thread which in turn will run this string using the ShellExecute Win32 command. The string will usually be a URL, which will allow the operating system to open the users default browser and navigate to the URL.