IF-THEN: Scan one column, find all the corr. values from next column and display

Hi,

I have categories I, II, III, IV under Column G. Column H has corresponding values. I have applied the general 'Filter' option to choose either I, II, III, IV or all for Column D

What I would like in Column F is: - scroll though Column D; If the filter criteria is 'II', then, find all the 'II's from Column D, add the corresponding values of II from column E and display in Column F
(The result in G would be, 5+3 = "8")


D E F
I 4
II 5
I 6
IV 8
II 3
III 2
III 1

Thank You
Angela