实体框架4.1 - 非关键列之间的关系

I have 2 entities that are related, but the legacy sql schema essentially has 2 key columns for the same table (not a 2-column key: see below). I need to create a relationship back to the 'faux key' column. Is there a way to do this declaratively in Entity Framework 4.1?I have 2 entities that are related, but the leg