str_insert_string_c

	str_insert_string_c(dest_string.i1a.r, main_string.i1a.r,
			    length_main.i4.v, insert_position.i4.v,
			    insert_string.i1a.r, length_insert.i4.v)

	This routine inserts a substring in the middle of another string.
	Neither "main_string" or "insert_string" are modified by this
	routine.  "dest_string" will be null terminated unless
	"insert_position" is negative.

	dest_string	output string (must be at least "length_main" plus
			"length_insert" characters long)  (This argument can
			point to the original string.)
	main_string	string to have substring inserted into it
	length_main	length of "main_string" (If a value of zero is passed,
			the length of the string will be calculated.)
	insert_position	position in "main_string" to insert "insert_string"
			(starts at 1)
	insert_string	string to insert into "main_string"
	length_insert	length of "insert_string" (If a value of zero is
			passed, the length of the string will be calculated.)

	This function requires the following include files:

	cbslib_h

	Related functions:

	str_insert_char_c, str_delete_char_c, str_replace_string_c

	C/C++ usage:

	char	dest_string[128];
	static const char	main_string[] = "insert here";
	static const char	insert_string[] = "string";
	int	length_main = 0;
	int	insert_position = 8;
	int	length_insert = 0;

	str_insert_string_c(dest_string,main_string,length_main,
			    insert_position,insert_string,length_insert);