Power Query, Transform Column by values in another columns

Hi,
I've attached a work book showing in excel what I would like to do in power query,
I have a budges for each row, and want to allocate it between each item in that row, so if A1 = 3 , B1 = 2 , A1 = ( Budget / 5 ) * 3

so;

 List.Accumulate ( listA, Source, (S,C)=>  
                                                     Table.TransformColumns( S, { C, (A)=> List.Count(  Text.Split(A,","))  } ))

Gives the number of items in each cell, I can then sum these in addcolumns and divide

Table.AddColumn(Custom1, "allocation", each Number.Round  (  [Budget] /   List.Sum ( { [DepC],[DeptA], [DeptD], [DeptB]} ),2),type number )

I then need to multiply this by the number in each cell by this, I hope the excel table will show exactly what I'd like to do.

I have thought about using addcolumns 'standard' multiply' ? the query accerAllocation is the one I've got furthest with so far.

Richard.