Looks like I'll have to be creative - {1}BAL[4]Q gives me the YTD balance as of the prior 4th quarter, and I will have to subtract from that {1}BAL[3]Q. But it works.
Unless you have a more elegant solution...
The Superspec explanations in column D could be clearer for the prior year codes - both M and Q. They don't specifically state that the figure might be zero as the current year codes do.
Steve