Rails - Jan 2006 - setting a query from another query

I have a table that lists other lookup tables. It has
id
description
list_table

I have a controller that takes care of editing this table itself - but 
what I''m trying to achieve is to allow the user to edit the tables 
referenced in that master list. so what I''d like to do is get the value
of list_table outa there (which I have) and plug it into a query that 
will show me a list of records from the referenced table.

I hope that makes sense :~)

Any ideas??

Cheers,
Eric.