Hi Nadya,
You were right, I had ControlSource and RowSource the same, that was silly. I think I've got it working the way I want it. Unfortunately, this is a part of the problem. Now, I have to make it working with Mere Mortals. The form where combobox resides is very complicated and it is not working so far but I am going to keep trying.
Thanks for your help
Regards
Igor