I've got a funky workbook that I have to use as my source.

The WB lists FMAP rates through the years in a straight line going down, so it's an easy matter to do a lookup to the current year. The problem is that when there's a change to any FMAP value, it goes in the workbook as a new sheet, with the Tab name the same as the day it went in. So, for instance, earlier this year I pointed my VLookup to tab "12-3-19". Now there are two new tabs, "03-26-2020" and "04-06-2020". Notice the naming isn't consistent. The only consistency is that the newest sheet is the leftmost sheet in the workbook.

How do I configure my formula to always look at the first sheet in the workbook?

BTW, I'm also having to change my formula from a simple VLookup, which scan DOWN a list, to a Lookup formula that scan's upward. I was starting to make that change when I noticed this further complication.

My simple Vlookup formula is this: 
=0.01*VLOOKUP(LEFT(A14,4)&"*",'\\12dal1001fs01\share10011\Budget\_Protected_Data\Source_Docs\FMAP_Rates\[HISTORY OF TEXAS MEDICAID PERCENTAGE MATCH_DO NOT DELETE.xlsx]12-3-19'!$A1:$E76,3,0)
Any help I can get would be greatly appreciated.