You can also do it inside the for each when you define the list, but in my opinion it is better to do it before (easier to read and debug)
Names Default To Here(1);
dt = open("$SAMPLE_DATA/Big Class.jmp");
For Each({colname, index}, Remove(dt << Get Column Names("String"), 1, 3),
show(colname);
);
Or if you collect list before, you can just loop over specific items
Names Default To Here(1);
dt = open("$SAMPLE_DATA/Big Class.jmp");
collist = dt << Get Column Names("String");
For Each({colname, index}, collist[4::N Items(collist)],
show(colname);
);
-Jarmo