Contacts to distribution lists

We are using OL2007 and Exch. 2007 srv

I have problem described below:

Because I do not want create Global distribution lists (have
multiorganisation exchange) because our lists contain persons who are not
members of our exchange server.

That is why I need to create personal DL:s which I share to my organisation.

However there is couple of challenges:

- First we have a need of maybe approximately 10 to 15 DL:s
- There could be about 1500 contacts in one DL
- One contact could be member of several DL:s
- I have excel sheet per each DL members, Names, addressess, emails and
other useful information

Scenario 1, easy but affects some maintenance problem:

- I do not create individual contacts, only paste email-addresses to the DL:s

This scenario 1 is for start very good and fast but problem is when
something change (or deleted) in one member of DL. Then I need to change
that information in every DL where that person is a member, not good

Scenario 2, probably more difficult to create but easier maintenance:

- First I create from Excel-sheet correct amount of contacts and f.e I give
a correct named gategory per one sheetmembers
- Then I create DL and I pick members from contacts

This is good for maintenance because when I change/delete contact
information and I update DL then information/mail-address is changing
according to contact information or that member is deleted from DL.

However I haven't found any idea to easily add hundreds members to DL
because option "select members" is not allow any way to sort contacts in a
way that I can pick those members easily. It gonna takes forever to pick
1500 member to DL from 6500 member contacts list.

Any suggestions? Is my information good enough? Sorry my poor english, my
native language is finnish

Btw. I have tried 3rd party plugin (4Team Send2) and it seems that it is
working but I need to know is there a way to do this in MS own tools?