Hi,
It's pretty straight forward. I'm assuming you're working at this programatically. What you need is the Item Names property (right click on the FPTerm on the block diagram and select create->property->Item Names.
This is a 2-D array of strings. You can then use the array .vi's to delete, insert and replace the elements you're interested in.
You say items in your question - if it's an item in the middle of a row, or the middle of a column, you'll have to replace with an empty string instead deleting, otherwise you'll lose your positioning in the columns and rows of the other data.
Hope that helps
(attached is a little .vi which takes in a control reference to the multi column listbox, and allows you to add, delete and replace parts of the list - it
's not fully featured, as there's no add element, or delete element, but delete element can be acheived by replace element with an empty string. Adding an element requires knowing whether you want to insert it into a row, or into a column or both)
S.
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