Combo Box Record Selection

I have a Main Form
Main Form [Event],[Category],[Judge Name]
The Main Form also has a subforms
Sub1[Event],[Category],[Judge Name],[Score],[Comments]

On the main form I have a combo box that is set to retrieve records that meet the combo selection. and thus the subform is related to display the corresponding records.

In my selection combo box I see all of the various selections as follows
[Judge Name],[Category],[Event]
and it is bound to the judges name

Problem Example:
Pull Down Values
1.[Sherry],[Fitness],[Mrs. Canada]
2.[Sherry],[Swim Suit],[Mrs. Canada]

In the above when i pull down the combo box to select and I select the first example above all is wonderful ; however if i want to select the second row the [Category] and [Event] Do not change and the information i input into the subform ends up being associated to the wrong category.

How do i bind a combo box to more than one [field] on the form

I have over 50 hours into this DB to this point and this is critical.