Can the element indices in a Table-Map-Manipulate structure be determined?

The attached notebook is a table populated by solving the equations inside a FindRoot structure.
I’m trying to come up with a Map process that detects negative numbers in column 3 and replaces them with revised numbers I calculate. I can acquire the element coordinates outside of the manipulate structure but if I try to wrap the table inside a Map structure I get no output.

Is there a way to keep track of the element position as the table is filled in Manipulate?

Thanks in advance,
G