Copy last formula in column and past into range

Every time you guys are able to get me over a hurdle, I think of something else.

Document is attached.

Cells with Formula starting with "=AT" in attached file is getting data from another source. The last time the file was opened was Jan 14, so the data was good up to Jan 13 (although you will just see errors).

Currently, the formula is in every cell for the whole year, however I don't want the the formula to search for the data, if the date hasn't passed. It's incredibly time consuming. (I removed the formula in the columns past Jan 13 to indicate what I'm looking for).

So, when I open the file on Jan 16, I need to find the columns with "=AT" in the formula, find the last cell in each of those columns, copy it, select the range from that date (the last date the file was open) to today, and paste the formula.

And the same if I open it on Jan 21. Find the last time it was updated, and fill in the appropiate cells, up to Jan 21.

Essentially, I want to fill the blank cells with formula when I run the macro, but only up to the current date.