Combo Boxes

Hi - I need to be able to change the list in a combo box, depending on what has been selected in a previous combo box. For example, I have ten combo boxes sitting in cells B1 to B11 and writing numerical values to C1 to C11. The first combo box has a list of jobs in a company ranging from Company Director down to Assistant. If Company Director is selected in combo box 1 in B1 I don't then want it to appear in the list for all the other combo boxes. However, if it isn't selected, I want it to appear in all the other boxes. Is there a way to make the population of all the boxes reflect choices previously made? Any help would be much appreciated.

Very many thanks oldchippy. MUCH appreciated