Is There A Way To Display Only Part of a Vocabulary?

Hello Everyone,
Is there a way (a view, an existing module, a swell hack), to limit the display of a vocabulary in a node editor?
For example:

Countries (Vocabulary)
- Africa
   - Kenya
   - South Africa
- Asia
   - Japan
   - Thailand

I would like to show off just the "Asia" part of this tree in a particular content-type's editing page-- specific to the content-type. I don't want to have two vocabularies (one for Africa; one for Asia). While I could make a new field and selectively pull from a term's children to populate the list (all via PHP), I do not see how I could then properly populate term_node on submission.

Any ideas?

Thanks in advance,

• Mike