I want to build a minimal program to illustrate a problem I am having with the Shell Lightweight API in a dialog-based MFC project being built in Visul Studio 2019. The API uses a file named shlwapi.h. That file is included somewhere in the header file tree in a project that was imported from Visual Studio 2008, but I don't know anything more than that. How can I ensure that it is included in my new project?