Formula needed - Hard

Hello everyone
I need help
Attached is the relevant worksheet, the first tab contains the task outline and objective

Soliciting or offering payment on this free forum is not allowed - please edit your thread title and its contents and the contents of the attachment to remove this offer of payment.

Administrative Note:

Welcome to the forum.

We would very much like to help you with your query, however the thread title does not really convey what your request is about. Tell us what you are trying to do, not how you think it should be done.

Please take a moment to amend your thread title. Make sure that the title properly explains your request. Your title should be explicit and not be generic (this includes function names used without an indication of what you are trying to achieve).

Please see Forum Rule #1 about proper thread titles and adjust accordingly. To edit the thread title, open the original post to edit and then click on Go Advanced (bottom right) to access the area where you can edit your title.

(Note: this change is not optional. Normally as you are new I would do this for you, however you have not indicated in your thread what this is about. You need to do so in the thread and in your thread title. No help can be offered until this is sorted out - sorry.)

I think you missed this bit:

The thread title does not really convey what your request is about. Tell us what you are trying to do, not how you think it should be done.

Please edit the thread title to tell us what you are trying to do and give details in your opening post.

I have removed the attachment - please replace it with one that does NOT include the offer of a reward.

When ALL of these things are done, you may receive help.

Do NOT open a duplicate thread. Do as I have instructed HERE and then I will clean up the thread.

Then take a moment to read our rules, please.

Your duplicate thread (whose title was NOT what I have asked for and whose opening post contained NO details of the problem) has been closed.

Which bit of "make your title descriptive of the problem you are trying to solve" and "give details in the opening post" are you not understanding?