Wanting to retrieve values from external workbook by searching name of column.

Alternatively, you would need to modify your database as illustrated in the SignalsMod2.csv
to search for the last item in a given list. There are formulas listed along the top row
This takes advantage of the MAX() Function and the VLOOKUP() and LARGE() functions.
This is where you would use

=VLOOKUP(LARGE(),RANGE,Column_In_Range,FALSE)