custom Excel spreadsheet design

I would like to have an excel spreadsheet dsigned which will calculate figures base on a drop down option. This spreadsheet will calculate telecommunication costs. The excel template willl have a logo on the top page The first column (a) that allows staff to enter the current telecommunication costs per line including the total cost for each line. This cost would add the total number of landline chargers per line. The second column (b) will allow different drop down options on all the types of new lines required on the new call rate plans. You will be able to choose the numebr of lines required, number of handsets needed on the new phone systems & type of internet plan required Column three (c) will have the % saving Column four (d) will show the overall savings