excel calculation queries

Folks,

could you please help me out the following

1. once vendor and sub group is selected , curresponding discounts are showing automatically. now for the highlighted, it needs to be mulitiply with the corresponding cell, when the vendor and subgroup is selected. could you please advise , how we can adchieve it

2. one of the other objective is , when i enter the value as price and select currency , the final cells should be automatically converted to aed . if i select the prices and currency aed , of course there would be no change . how can i acheive this

any advises

Regards,
Sid
test-2z.xlsx