Combo Box Format

I have a combo box with three columns, something like:

Category Item ID
AOI broken 27
AOI no staff 32
SMT fat 1
SMT lazy 2
SMT short 3
TP awake 7
TP bashful 42
TP candy 45
TP dopey 8


[ID] is my bound column. The list is actually about 90 records long; [Category] is just used to help the user narrow down the list to the correct Item. I want to keep the list sorted by [Category], [Item].

After the user makes a choice, what I want to stay visible on-screen, as a confirmation of the choice that the user made, is [Item]. However, what shows on the screen is [Category]. Is there any way around this? It seems like what shows on the screen is always just the contents of the first column.

I realize I could do this by using a separate combo box for [Category], to first limit the contents of [Item]. But my form is a continuous form, and this seems likely to be very confusing to the user, because when you change [Category] in one record, it looks like it changes all of them, and the previous [Item] selections look like they disappear.

Thanks for any suggestions