Depending on your CUE version, the supported languages are Danish, US English, British English, French, German, Italian, Portugese, and Spanish. CUE 2.3.1 currently supports only US English. Please see the following links for confirmation.
Release Notes for CUE 2.0
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/prod_release_note09186a0080450c0c.html
Release Notes for CUE 2.1
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/prod_release_note09186a00803d3c28.html
Release Notes for CUE 2.3
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/prod_release_note09186a0080679b50.html
Hope this helps. If so, please rate the post.
Brandon