Using psql to insert character codes

Say using psql I wish to insert a character into a VARCHAR / TEXT / whatever
column using the its hexadecimal representation in the relevant character set
/ encoding. E.g.: C3A4, which represents the character 'ä' (lower case a with
umlaut) in UTF-8.

I can do this:
INSERT INTO my_tbl (unitxt) VALUE(encode(decode('c3a4','hex'), 'escape'))

Is there any other, shorter way of doing the same?

Ian Barwick
barwick(at)gmx(dot)net