/sys$common/syshlp/helplib.hlb CC, Run-time functions, mv[w]delch  *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 delete the character on the specified window.  The
  mvdelch macro acts on the stdscr window.

  Syntax:

       #include <curses.h>

       int mvdelch(int y, int x);
       int mvwdelch(WINDOW *win, int y, int x);