Rename files in C++ with wildcards across directories?

Renaming Files in C++ Across Directories with Placeholders, and the Simplicity of Renaming Files in Windows

1. Renaming Files Across Directories with Placeholders in C++:
2. Information on Renaming Files Across Directories in C++:

1.) Renaming Files Across Directories with Placeholders in C++:

#include <iostream>
#include <windows.h>

int main()
{
  const char* directory = "C:\\Path\\To\\Directory";
  const char* placeholder = "*.txt"; // Placeholder for files to be renamed

  WIN32_FIND_DATA findFileData;

  HANDLE hFind = FindFirstFile((std::string(directory) + "\\" + placeholder).c_str(), &findFileData);

  if (hFind == INVALID_HANDLE_VALUE)
  {
      std::cerr << "No matching files found." << std::endl;
      return 1;
  }

  do
  {
      const char* oldFileName = findFileData.cFileName;
      const char* newFileName = "new_file_name.txt"; // New file name

      std::string oldFilePath = std::string(directory) + "\\" + oldFileName;
      std::string newFilePath = std::string(directory) + "\\" + newFileName;

      if (std::rename(oldFilePath.c_str(), newFilePath.c_str()) == 0)
      {
          std::cout << "File " << oldFileName << " successfully renamed." << std::endl;
      }
      else
      {
          std::cerr << "Error renaming " << oldFileName << "." << std::endl;
      }
  }
  while (FindNextFile(hFind, &findFileData) != 0);

  FindClose(hFind);

  return 0;
}

2.) Information on Renaming Files Across Directories in C++: