how set "xml:lang" attribute?

i need supplement xml:lang charge bottom xml node outbound request biztalk.

this bound value, competence set schema something.

this i wish out:

<catalog xml:lang="nb-no">
...
</catalog>

i've attempted interpretation charge "xml:lang", nonetheless doesn't grant me ":" schema.

this blunder summary i get:

invalid 'name' charge value
'xml:lang': ':' character,
hexadecimal value 0x3a, during position 3
within name, can't enclosed in
name.

is there another proceed insert ':' biased charge name biztalk?

can anyone tell me this?

i'm controlling biztalk 2006 orchestration.