Reading content of array formula
 

Is there a way to determine the first row that is used in an array from
another cell.
For example, in cells F7:G11, I have the following array:

{=LINEST(B25:B169,A25:A169,TRUE,TRUE)}

I would like another cell, say F5, to indicate the cell identified (in this
case B25 or A25). The reason is that I would then like to use a match
function or a lookup function to tell me the date that corresponds with that
point in the array.

I tried using =mid(F7,10,2). But that just returns the digits from the
resultant calculation.

Thanks.