adding dynamic items to a drop down list which contains standard items

I have a spreadsheet which has 6 different events titled 18-01 thru 18-06 (year and event) across the top. Listed in column A going down are check point events, column B has various numbers 180-1 (counting backwards) which represent the number of days prior to the start date these tasks must be accomplished. Column C has a formula to calculate the todays date minus the number in B so I can track stuff by actual date. So listed under the 18-01 thru 18-06 are various dates. I have manually built drop down boxes for each cell in the spreadsheet, well over 500 of them (time consuming) The drop downs contain (complete, working, overdue, N/A, the original date calculated for that cell and a blank so I can change a date due to holiday or weekend) Is there a way to have the standard (complete, working, overdue, N/A and blank) items but dynamically add the correct date (depending on which column it falls in) so I can set up in the first cell a drop down and simply copy to all the remaining cells?