Here's a complication: some of the columns in my groups derive from a virtual join. So when I perform a <<Get Column Group("groupname") on those particular groups, the list that results looks like this:
group = {:LocalColumnA, Referenced Column("ForeignColumnA", Referenced Column("ForeignColumnB", Reference(Column(:ForeignLinkReferenceColumnA), …}
and the group<<hide(1) action only succeeds on the local columns, not on the foreign (virtually joined) columns.
Yet when I do this in the manual interface, the virtually joined columns respond just fine to a manual Hide/Unhide menu selection. Aaargh.