Creating an Umatched/Duplicates Query?

[CSatGal]

I'm trying to create a query that will:

-let me enter a particular SatisfactionCode when I run the query to limit my results (using Like [Enter Satisfaction Code or Press Enter for all Satisfaction Codes]& '*' as my criteria) and show all of the CaseIDs associated with that code
-show all of the other SatisfactionCodes associated with the CaseIDs above

So far, no problem... I've created a report that lists the SatisfactionCode that I specify, the CaseIDs associated with that code, and all of the other codes associated with each CaseID. What I'd found, though, is that the SatisfactionCode (for example, CA32) is listed again in the second SatisfactionCode column- ie the codes associated with the CaseIDs associated with the specified code (I hope that made sense). Is there a way to create an IsNot criteria in the second SatisfactionCode field that will self-populate when I type in a value in the first SatisfactionCode field when prompted to do so? Or should I use another method of eliminating these "duplicates" so as to enable the "press enter for all Satisfaction Codes" (see above) to work as well??

Thanks in advance for your help and advice!!