This may not be a question so much about programming as it is about
technique.

To start with, I am given a simple 2D grid that makes up a schedule for
performing the same process on a group of items.

For column heads use Step A, Step B, Step C, and Step D. For row heads
use the object for which the step must be taken: Item 1, Item 2, Item
3, through Item 10. Within this grid is data: the due dates (Item 2
must have Step C completed by 5/1, Step D by 5/3, etc.).

I've written a script that runs through every data cell and copies a
reference to a database-like table on a new worksheet that reports the
full value of the data. Thus my new sheet has "Item," "Date," and
"Task" as the column heads and sets out all of the information on a
long narrow ribbon. (For example, one cell on the original sheet that
reads "5/10" is written out to three cells with values Item 6, Step 4,
and 5/10 respectively.) Now I can sort this by date and see that, say,
on 5/3 Step 1 of Item 3 must be done, Step 2 of Item 2 must done, and
so on. And by using references, if the first sheet is updated the list
is too.

Question: Can I use this ribbon of dates to build a new matrix? If so,
how?

For example, one client wants to have a matrix where the column heads
are Steps and the row heads are Dates, and the various items due appear
in the data. Is this kind of transposition feasible without manual
assistance?