try this approach...
for part A,
you can write your expression something like: rangesum(before( sum(Sales),0,Month))
month is number of the month (if your calendar month use num(Month))
its difficut to get the part B, but as an alternative you can include a background expression
like below, which highlights all those values exceeding targets. you can still modifly the expression to highlight the one month (ex: Aug)
Attached with answer. I thing i did was find the running total starting from Jan to Dec. Also I created a variable in the back-end to set the Target amount. Please go through the code and the tables created on the front end.
Test1.qvw 155.8 K