Hi Neil,
@ Andy - sorry, wrong.
there is a simple and standard way for achieving your requirements. BPC itself provides the solution for you.The number of columns doesn't matter at all. It will show the sum for all your columns. As confirmation please see the screen below to make sure I met your requirements:
Report:
The report above shows the desired result without any manual entered local member. For achieving this simply create a report with a dimension in rows (here entity) and your dimension PRODUCT in columns. Select in your REPORT member selection the desired products to be summed up - here I took ProductA and ProductB. Now go to the sorting properties for the product dimension in EPM Editor and make the settings as follows:
1. Enable Member Sorting
2. Group by Property HLEVEL
3. Select AFTER tab
4. Set flag Create Local Member Named - After (once you set the flag the local member formula will automatically filled by system)
5. Press OK
Now you got a report with ProductA and ProductB in columns plus a TOTAL column. After these steps create a new report with sharing row axis. Select the new products - I took ProductA and ProductC. Repeat the sorting settings described above and you will get the report shown in screen.
Hope this will help you,
Karsten