Add a Region which contains the table header columns for the screen that you want to customize using the Device Application Designer. Then modify the generated gap class:
protected void createControls() {
super.createControls();
if (regionManager1.getManager() != null) {
Manager m = regionManager1.getManager();
m.delete(regionManager1);
layoutManager.delete(m);
}
setBanner(null);
VerticalFieldManager vfm = new VerticalFieldManager();
vfm.add(navigationBarField);
regionManager1.setColumnPercentage(cellTable1.getTableConfig()
.getColumnPercentage());
vfm.add(regionManager1);
layoutManager.setScreenHeader(vfm);
setBanner(vfm);
}