how can i insert a column value at a specified row

Question

how can i insert a column value at a specified row

Answer 1

Not sure if you are trying to insert a new row or update a row that meets certain criteria. If the second is true, you need:

UPDATE table_name 
SET column1 = value, column2 = value2 
WHERE some_column = some_value

Answer 2

Try taking a look at UPDATE rather than INSERT.