Well it doesn't matter so much to me, in the old files all the formulas can be deleted or can remain (would be slightly better probably).

Ye actually this is what I asked for, I want to keep the numbers (results from all 50k old files from cell N2) on one worksheet. And as I said, it would be very helpful, if the name of the particular old file could match to the particular result from N2 (the name and the number would be in the same row).