Cognos Multi Parameter Selection Problem

[cbflex]

I'm having a weird complex issue in Cognos.

I have a prompt page with a Radio Select Prompt with 4 Choices, numbered 1-4. The prompt allows for multiple values.

There are 10 queries that I have placed in a Union.

Each query has a column named, Category, with a unique number to identify that query. The numbers go from 1-10.

This is how I want the report to run.

When you select Choices 1 and 2, the output should be Show Queries with Categories 1,2 and 5.

When you select Choices 1 and 3, Show queries with Categories 1,3, and 6.

When you select choices 1 and 4, Show queries with Categories 1,4 and 7.

When you select choices 2 and 3, Show queries with Categories 2,3 and 8.

when you select choices 2 and 4, Show queries with Categories 2,4 and 9.

When you select choices 3 and 4, Show queries with Categories 3,4 and 10.

I've developed numerous case statements to make this work, and I'm having great difficulty getting this to work. The reason for my difficulty is for example, when the use selects Choices 1 and 3, Cognos apparantly only first looks at the first number, "1". It then thinks, "Does "1" exist IN (1,2 and 5)? YES. Show queries with Categories (1,2 and 5).

It'll also show the other queries where "1" exists...

How do I get Cognos to make sure that "ALL" the values that are selected in the Prompt, exist IN the Categories, so that if I select 1 and 3, the only queries I should see are (1,3 and 6).