I am not sure I understand your requirement. If it's about getting fiscal year on top of the Months only, I am afraid that might not be feasible like that. Alternatively, you could create Fiscal Year in the script and then use Fiscal Year and Month as dimensions, and then pulling them to the columns is what usually should be done. However, since you have few more calculations which are independent of the financial year context, that possibility also looks grim to me. I can think of trying it with valuelist() as a chance (along with the year, month as dimension approach), but not sure if that could help or not here.
Or, else, try calculating the additional calculations in the script or as calculated dimension (not a good recommendation though). and then use the dimensions and pull across solution.
