[Koha] Excluding a ccode in a report

Hi everyone- I'm wanting to run a report for a particular itype in our collection but exclude a certain ccode that exists within the itype. So, I want a report WHERE items.itype='LKBK' but not items.ccode='LKIX'. I've tried a few different ways to express the "not" part, but nothing I tried worked. Could anyone tell me the correct SQL wording to do this? TIA ~Joy Joy M. Banks Catalog Librarian Roux Library Florida Southern College 111 Lake Hollingsworth Dr. Lakeland, FL 33801 (863)680-4736 jbanks@flsouthern.edu