I have been trying for a while, I need to get the same values from almost 5 years worth of daily workbooks. They are labelled sequentially (2017.08.14, 2017.08.15, 2017.08.16 etc), but I have tried several formulas that insert this into the full address string and they tend to end up with REF! I am quite happy to use a VBA solution, or really any approach that doesn't involve manually opening and copying several values over 1500 spreadsheets.
The answer I feel might be closest was when I attempted; =INDIRECT("'S:\Reports\2017["&E2&"]Totals'!$C$17") where E2 refers to the cell containing the date string for today, and C17 is tthe target cell in the other workbook, but despite the fact that following it step by step produces =INDIRECT("'S:\Reports\2017[2017.08.19]Totals!$C$17) it still produces REF!, even though simply typing that formula in a cell works fine.