Set a modifier only for the second price list of a customer

Hi,

many of my customers have their special primary price list. In this list are a few items, which they get for a special price.

In the second price list of this customers are all items and some of them get a discount (in percent) of this completely list.

Now I'm looking for a modifier for the discount of the second price list.

Thanks in advance!

Kind regards

CfE