/sys$common/syshlp/helplib.hlb CC, Run-time functions, mv[w]addch  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Curses Screen Management macros that move the cursor to coordinates
  (y,x) and add the character ch to the specified window.  The
  mvaddch macro acts on the stdscr window.

  Syntax:

       #include <curses.h>

       int mvaddch(int y, int x, char ch);
       int mvwaddch(WINDOW *win, int y, int x, char ch);