I have a column that has 44 active rows in it and I have attached each cell
in those 44 rows to a data validation list.

I would like to know how to tell Excel, that if an item is selected from the
drop down list, that it is removed from the choices and conversely if a
person deletes the chosen item from one of the 44 cells, it is placed back
into the list for choices.

I am guessing a Visual Basic macro is going to be employed here and I don't
mind if the drop down list gets moved from the workbook and placed straight
into the coding of the macro.

I thank you for any help you can offer.

Tofer