I'm trying to exclude a column called "sortOrder" in a set of columns. I'm specifically trying to use a regular expression instead of simply using the column filter to get rid of that column, because I've often seen that some new columns (i.e - the input data changes and has different columns) creep into that filter node and also may get excluded etc.
Anyhow, I've noticed that there's no way of negate-matching a regular expression in the Column Filter node. Perl for example allows both positive and negative matching with regular expressions. This node however allows just positive.
So, I think that negative-matching would be useful :)