Script For Calculation Of Sum Based On Two Conditions

I have the following spreadsheet as an example:

A
B
C
D
E
F
G
H

1
Article/hours
10
27
33
15
33
40
40

[Code] ........

Column A contains codes for certain work activities.Row 1, from Column B and beyond contains number of worked hours.The matrix is populated with letter "D" to mark activity for particular work code for particular amount of worked hours.

My goal is to have a formula/script that analyzes this matrix, and returns a total amount of worked hours per work code. In other words, if a cell contains the letter "D", the amount of hours in Row1 for that particular column should be added to the total amount for that particular code, let's say code "501" as an example. For this example, the result should be a cell, lets say "A8", that contains the total amount of hours spent on code 501: in this example - 213 hours.