TPM - Planning on Custumer Hierarchy but exclude some customers

Hi,

within TPM it is possible to plan on different Account levels (Single Account, Hierarchy, Target Group).

We've got the requirement if a promotion is planned on a customer hierarchy node, the user needs to have the possibility to

exclude individuel customers underneath this node.

I didn't find any exclusion possibility for customers (only for products).

As anybody experience or an idea of customer exclusion within trade promotion management ?

We are working with CRM 7.0.

Many thanks

Andreas