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

  Converts its value argument to a null-terminated string of ASCII
  digits and returns the address of the string.

  Syntax:

       #include <stdlib.h>

       char *fcvt(double value, int ndigit, int *decpt, int *sign);