Zachary,
If I understand you correctly, all you need to do is for the second combo box, go to the options area for the question and select SLQ driven. You would then write your sql statement to be something like this:
SELECT FieldName as QuestionOption, FieldID as QuestionOptionValue
FROM TableName
WHERE ModuleID = '$(ShortName)'
FieldName is the name you want displayed, and FieldID is the value you want stored for the second combo box. TableName will be the name of your table where FiledName and FieldID are being pulled from, and ShortName will be the short name used for the first combo box. But the main point is that the table you are going to use to load your options, must contain ModuleID
I usually do this with the second question being hidden, and then Display that question when the first question is answered with a Question Event to display hidden question. If you want the second question to always be visible, you can always use the Set question default / return SQL... option in the question event, and select sql driven, and place you sql statement there.
Hope this helps.
Steve