Try this trick. Create two copies of your field. Format one copy of the field as your drop down list with the arrow. Resize this copy of the field so that it is only the width of the arrow. Place it to the left of the other copy of the field. You may want to format the copy of the field without the list to also be a drop down list but without the arrow option.
Thanks - that looks good to me - now to run it past the customer