How to reduce the top Node Value by several accounts - wihout having them displayed in EPM?

Hey Folks,

following Situation we have a very Long ACCOUNT hierarchy and in Terms of providing a better Performance I just put the top nodes which show the total value of the accounts in the Report.

Structure is like this:

1. NodeA (5000€)
1.1. ACCOUNTA (1000€)
1.2. ACCOUNTB (1000€)
1.3. NodeB (3000€)
1.3.1 ACCOUNTC (2000€)
1.3.2 ACCOUNTD (1000€)

2.NodeC(3000€)
2.1. ...... and so on

So the requirement is here to show only the top nodes of the hierarchy.

1.NodeA(5000€)
2.NodeC(3000€)

BUT - it si requested to leave a few accounts out of the total Value. So in this example we could say ACCOUNTD should be left out:

1. NodeA (4000€)
1.1. ACCOUNTA (1000€)
1.2. ACCOUNTB (1000€)
1.3. NodeB (2000€)
1.3.1 ACCOUNTC (2000€)

2.NodeC(3000€)
2.1. ...... and so on

But in the Report we don't show the Accounts (that's why we can't exclude it with a filter by property or so) and that's why we can't use the calculate parents in hierarchies Feature from EPM Report Editor)

We just have

1.NodeA(5000€) --> and want to exclude the value of ACCOUNTD here --> so it should just Display 4000€
2.NodeC(3000€)

Does somebody has an idea how to realize that in a performant way? Because i realized it already via Excel formulas and EPM local members but this killed the performance of the Report....

Thanks in advance!
regards from Germany!