Trying to something with excel (not an expert) and struggling

I have five columns with 10 rows
There is row 11 which is the sum of each row (ie A1 to A10 is totalled in A11)
What I want to do is place a marker in column five on any row and it show
the total of the column assuming column five has a marker.

example

10 20 30 40 *
10 20 30 40 *
10 20 30 40
10 20 30 40
20 40 60 80 Total row

I cannot figure out the function required for row 11
Not sure if that makes sense - any help would be great