how to fill the non exist data in drop down using vba form excel sheet

hello all,
i am create drop down list in my user form. i want fill data in to the list.
how to fill drop down list in 'B" column(Shee1) text only if "az" column have "Working" (sheet 1.)
after submit the data in to Sheet2 the particular "B" column text row , "AZ" cloumn cell text will change into "Assigned".



Thanks for advance