This example enumerates all of the object classes that process the "MyFormat" clipboard format.

HATOMTBL   hAtomTable = NULLHANDLE;
ATOM       aFormat = 0,aClass = 0;
CHAR       szClassName[CCHMAXSTRING];

/* Find the system atom table  */
hAtomTable = WinQuerySystemAtomTable();
if (hAtomTable)
{

   /* Add an atom to the system atom table for the clipboard format  */
   aFormat = WinAddAtom(hAtomTable,"MyFormat");
   if (aFormat)
   {

      /* Enumerate the object classes that process the specified
       * clipboard format */
      aClass = _wpclsEnumClipboardClasses(aFormat,(ATOM)0);
      while (aClass)
      {
         if (WinQueryAtomName(hAtomTable,
                              aFormat,
                              szClassName,
                              sizeof(szClassName))
         {
            /***** Process the class whose name was returned in szClassName *****/
         }
         aClass = _wpclsEnumClipboardClasses(aFormat,aClass);
      }

      /* Delete the atom from the system atom table  */
      WinDeleteAtom(hAtomTable,aFormat);
   }
}