SUM formula arguments using data from multiple cells

Desired formula =SUM(feb6:feb27!D7)

there are a few worksheets between feb6 and feb27, the column "D" is constant, however the row number can change from week to week. I want to be able to build the formula going down 50 or 60 rows and have the "7", or row number read into the desired formula.

I have a column with numbers like so

7
11
15
19
23
27
33
38


I need the formula to read those numbers in, so that the formula will read:

=SUM(feb6:feb27!d7)
=SUM(feb6:feb27!d11)
=SUM(feb6:feb27!d15)
=SUM(feb6:feb27!d19)
=SUM(feb6:feb27!d23)
=SUM(feb6:feb27!d27)

etc, etc....

Any help will be much appreciated as it will save me a lot of time.

Thanks in advance.


dale