utf-16 hex to binary data (the word), how?

[MacBoy]

for example this word:
http://www.unicode.org/cgi-bin/GetUnihanData.p l?codepoint=55c 0

UTF-16 hex is 55C0, UTF-8 is E5 97 80, and use hexdec(55C0) can get dec 21952.

I know that to display the word from the UTF-8 is using pack("H*", "e59780")

but now, for example, I only have the UTF-16 hex, 55C0, how can I display the word? any idea?