_CP_soundex is equivalent to the result = soundex(string, type) BASIC statement.
int _CP_soundex(CPSTR** result, CPSTR* string, int type)
This function returns -1 if an error occurs. The error code is contained in _CP_errno.
/* Prints "H000". */
CPSTR * s = _CP_mkstr("hi");
_CP_soundex(&s,s,0);
_CP_print(s);