encode-coding-char

encode-coding-char is a compiled Lisp function in `mule-cmds.el'.

(encode-coding-char CHAR CODING-SYSTEM &optional CHARSET)

Encode CHAR by CODING-SYSTEM and return the resulting string.
If CODING-SYSTEM can't safely encode CHAR, return nil.
The 3rd optional argument CHARSET, if non-nil, is a charset preferred
on encoding.