Allocation issue

Hello Experts,

I am writing an allocation script for allocating cost but I am facing some issues in my logic script.

Here is the scenario,

I have 2 additional dimensions in my model (Product and Cust_Group) Hierarchy of these dimensions are listed above in the figure. Apart from this Sales volume is already in the database with product and cust_group at base level. Now I have entered a total amount with product -> No_Product and Cust_Group->Input 100000, 200000 300000 for Jan, Feb and March.

Now what I need to do is to allocate this total amount in Cust_Group and Product according to the sales_volumes that are already in the system.

I hope this you guys have understand what I need and guide me what should I write in my logic script to achieve this scenario. My script logic is written below.

*XDIM_MEMBERSET ACCOUNT=FIXED_COST_GROSS

*XDIM_MEMBERSET CATEGORY =Plan

*XDIM_MEMBERSET PRODUCT= NO_PRODUCT

*RUNALLOCATION

  *FACTOR=USING/TOTAL

   *DIM CUST_GROUP   WHAT = INPUT ;   WHERE =BAS(NATIONAL);  USING =<<<; TOTAL=<<<

*ENDALLOCATION

Regards