Okay, so I've got my User Entity all setup now, the way I think I want

What i WANTED to do was to change the Location (L) attribute to be a DN
Lookup Display that would query the User Entity and find the possible
values we have stored in eDir and let you select from that list (as
opposed to having to manually enter a drop-down list).

I guess:

1) Is there a way to do this? We have about 100 location entries
(meaning DIFFERENT names).

2) If so, do I make a diff. entity called like: Location Lookup? Or
do I point it to my User Entity and tell it to find "L"?

Which, BTW, I tried (told it to look at User Entity, Attribute of
Location and it came back with like 1,519 undefined results).