AFAIK, it is not implemented in the Xojo ListBox.
So, I was thinking to ask the user the column he want to move and the location # (Insert before user given column number), then reload the ListBox contents with the ‘new values’ (load the text into different Columns as asked by the user).
Then I was asking myself if an import window with two ListBox (import data on left, load order on the right), then load the data accordingly can be a better idea.
Your opinion ?