DBCombo & Listfield

I'm using DBCombo (VB 4.0) in my application. My Listfield property is using a "description" instead of "code" column from a table. Is it possible to check the primary key ("code" column) for the record that corresponds to the "description" column in the table just by using another property. Or I have to use a query to select the "code" for that "description". The problem is the "description" column may not be unique.