I know it is possible to set up a Combo-box with multiple columns...

What I'm not sure about is how to set it up so that, as I change from one item to the next, I get a message (somewhere) that gives me ToolTip kind of information about the current item.

For instance:
The combo box may contain a list of services we provide....
service-1
service-2
service-3
service-4a
service-4b
service-4c
service-5
service-6a
service-6b
service-7

service-4a is the same as service-4b and service-4c, with the only difference being the state (Florida vs. New York vs. Texas) that the service involves. Actually several services has a list of several states that apply to that service name.

When the user is sitting on service-4a, I'd like them to see that service-4a applies to "Florida, Georgia, Texas, South Dekota". And
when the user is sitting on service-4b, I'd like them to see that service-4b applies to "New York, Ohio, Maine". etc etc.

How can I do this?