Modifiers - List Qualifiers - Can there be multiple AND's and OR's in a List

Hi thanks in advance.

We are wanting to build a matrix of regional pricing modifiers.

We are going to qualify the list initially with a set of OR's for a list of customers, i.e. any one of those customers - so I am going to number them 1 to 100 say.

Those customers maybe ordering off 2 different price lists - so it needs to be either any of those customers with at least one of the price lists.

If I had just a single price list I could number it -1 as the AND statement.

But i am not sure how to setup the numbering if a customer can use either of those price lists - but must use at least one.