[Zope] iterating over key/value pairs

[John Hunter]

I would like to dynamically generate a list with an HTML SELECT tag
where the displayed values are strings and the returned value is an
integer code associated with that string

I have access to two External Methods, one returns a list of strings
and the other returns a list of codes associated with those strings:
get_descriptions() and get_codes()

The DTML I currently have is 


<SELECT NAME="race">
  <dtml-in expr="get_descriptions()">
    <OPTION VALUE="<dtml-var sequence-item>"><dtml-var sequence-item></OPTION>
  </dtml-in>
</SELECT>

but this returns the string selected, and I want the code returned, as
I indicate below with 'code-here'

<SELECT NAME="race">
  <dtml-in expr="get_descriptions()">
    <OPTION VALUE="code-here"><dtml-var sequence-item></OPTION>
  </dtml-in>
</SELECT>

I can add or modify the External Methods to return something more
appropriate if necessary.  Is there a way for an external method to
return objects that would have 'code' and 'description' attributes
that dtml-var could access?

Thanks,
John Hunter