I'm assuming you've used google alread so:
not using vc++ so don't know about here is some the first I found on a site and modified it, the second I coded to test writing macros with the #define directive
Here is one site that talks about macros.
** This example illustrates some predefined macros.
# define CONFORM "conforms"
# define CONFORM "does not conform"
system("TITLE C macros");
printf("Line %d of file %s has been executed\n", __LINE__, __FILE__);
printf("This file was compiled at %s on %s\n", __TIME__, __DATE__);
printf("This program %s to ANSI/ISO standard C\n", CONFORM);