CopyFile function copies an existing file to a new file. 

BOOL CopyFile(

    LPCTSTR lpExistingFileName,	// pointer to name of an existing file 
    LPCTSTR lpNewFileName,	// pointer to filename to copy to 
    BOOL bFailIfExists 	// flag for operation if file exists 
   );	
 

Parameters

lpExistingFileName

Points to a null-terminated string that specifies the name of an existing file. 

lpNewFileName

Points to a null-terminated string that specifies the name of the new file. 

bFailIfExists

Specifies how this operation is to proceed if a file of the same name as that specified by lpNewFileName already exists. If this parameter is TRUE and the new file already exists, the function fails. If this parameter is FALSE and the new file already exists, the function overwrites the existing file and succeeds.